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Posted to commits@commons.apache.org by gg...@apache.org on 2019/10/29 14:38:37 UTC

[commons-lang] branch master updated: Sort members.

This is an automated email from the ASF dual-hosted git repository.

ggregory pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-lang.git


The following commit(s) were added to refs/heads/master by this push:
     new 89d2edb  Sort members.
89d2edb is described below

commit 89d2edbf1726b8cd512076ded14b6d05f0840d23
Author: Gary Gregory <ga...@gmail.com>
AuthorDate: Tue Oct 29 10:38:34 2019 -0400

    Sort members.
---
 .../java/org/apache/commons/lang3/ArrayUtils.java  | 13590 +++++++++----------
 1 file changed, 6795 insertions(+), 6795 deletions(-)

diff --git a/src/main/java/org/apache/commons/lang3/ArrayUtils.java b/src/main/java/org/apache/commons/lang3/ArrayUtils.java
index 7569bf7..a35dde9 100644
--- a/src/main/java/org/apache/commons/lang3/ArrayUtils.java
+++ b/src/main/java/org/apache/commons/lang3/ArrayUtils.java
@@ -46,99 +46,99 @@ import org.apache.commons.lang3.mutable.MutableInt;
 public class ArrayUtils {
 
     /**
-     * An empty immutable {@code Object} array.
+     * An empty immutable {@code boolean} array.
      */
-    public static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
+    public static final boolean[] EMPTY_BOOLEAN_ARRAY = new boolean[0];
 
     /**
-     * An empty immutable {@code Class} array.
+     * An empty immutable {@code Boolean} array.
      */
-    public static final Class<?>[] EMPTY_CLASS_ARRAY = new Class[0];
+    public static final Boolean[] EMPTY_BOOLEAN_OBJECT_ARRAY = new Boolean[0];
 
     /**
-     * An empty immutable {@code String} array.
+     * An empty immutable {@code byte} array.
      */
-    public static final String[] EMPTY_STRING_ARRAY = new String[0];
+    public static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
 
     /**
-     * An empty immutable {@code long} array.
+     * An empty immutable {@code Byte} array.
      */
-    public static final long[] EMPTY_LONG_ARRAY = new long[0];
+    public static final Byte[] EMPTY_BYTE_OBJECT_ARRAY = new Byte[0];
 
     /**
-     * An empty immutable {@code Long} array.
+     * An empty immutable {@code char} array.
      */
-    public static final Long[] EMPTY_LONG_OBJECT_ARRAY = new Long[0];
+    public static final char[] EMPTY_CHAR_ARRAY = new char[0];
 
     /**
-     * An empty immutable {@code int} array.
+     * An empty immutable {@code Character} array.
      */
-    public static final int[] EMPTY_INT_ARRAY = new int[0];
+    public static final Character[] EMPTY_CHARACTER_OBJECT_ARRAY = new Character[0];
 
     /**
-     * An empty immutable {@code Integer} array.
+     * An empty immutable {@code Class} array.
      */
-    public static final Integer[] EMPTY_INTEGER_OBJECT_ARRAY = new Integer[0];
+    public static final Class<?>[] EMPTY_CLASS_ARRAY = new Class[0];
 
     /**
-     * An empty immutable {@code short} array.
+     * An empty immutable {@code double} array.
      */
-    public static final short[] EMPTY_SHORT_ARRAY = new short[0];
+    public static final double[] EMPTY_DOUBLE_ARRAY = new double[0];
 
     /**
-     * An empty immutable {@code Short} array.
+     * An empty immutable {@code Double} array.
      */
-    public static final Short[] EMPTY_SHORT_OBJECT_ARRAY = new Short[0];
+    public static final Double[] EMPTY_DOUBLE_OBJECT_ARRAY = new Double[0];
 
     /**
-     * An empty immutable {@code byte} array.
+     * An empty immutable {@code float} array.
      */
-    public static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
+    public static final float[] EMPTY_FLOAT_ARRAY = new float[0];
 
     /**
-     * An empty immutable {@code Byte} array.
+     * An empty immutable {@code Float} array.
      */
-    public static final Byte[] EMPTY_BYTE_OBJECT_ARRAY = new Byte[0];
+    public static final Float[] EMPTY_FLOAT_OBJECT_ARRAY = new Float[0];
 
     /**
-     * An empty immutable {@code double} array.
+     * An empty immutable {@code int} array.
      */
-    public static final double[] EMPTY_DOUBLE_ARRAY = new double[0];
+    public static final int[] EMPTY_INT_ARRAY = new int[0];
 
     /**
-     * An empty immutable {@code Double} array.
+     * An empty immutable {@code Integer} array.
      */
-    public static final Double[] EMPTY_DOUBLE_OBJECT_ARRAY = new Double[0];
+    public static final Integer[] EMPTY_INTEGER_OBJECT_ARRAY = new Integer[0];
 
     /**
-     * An empty immutable {@code float} array.
+     * An empty immutable {@code long} array.
      */
-    public static final float[] EMPTY_FLOAT_ARRAY = new float[0];
+    public static final long[] EMPTY_LONG_ARRAY = new long[0];
 
     /**
-     * An empty immutable {@code Float} array.
+     * An empty immutable {@code Long} array.
      */
-    public static final Float[] EMPTY_FLOAT_OBJECT_ARRAY = new Float[0];
+    public static final Long[] EMPTY_LONG_OBJECT_ARRAY = new Long[0];
 
     /**
-     * An empty immutable {@code boolean} array.
+     * An empty immutable {@code Object} array.
      */
-    public static final boolean[] EMPTY_BOOLEAN_ARRAY = new boolean[0];
+    public static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
 
     /**
-     * An empty immutable {@code Boolean} array.
+     * An empty immutable {@code short} array.
      */
-    public static final Boolean[] EMPTY_BOOLEAN_OBJECT_ARRAY = new Boolean[0];
+    public static final short[] EMPTY_SHORT_ARRAY = new short[0];
 
     /**
-     * An empty immutable {@code char} array.
+     * An empty immutable {@code Short} array.
      */
-    public static final char[] EMPTY_CHAR_ARRAY = new char[0];
+    public static final Short[] EMPTY_SHORT_OBJECT_ARRAY = new Short[0];
 
     /**
-     * An empty immutable {@code Character} array.
+     * An empty immutable {@code String} array.
      */
-    public static final Character[] EMPTY_CHARACTER_OBJECT_ARRAY = new Character[0];
+    public static final String[] EMPTY_STRING_ARRAY = new String[0];
 
     /**
      * The index value when an element is not found in a list or array: {@code -1}.
@@ -148,3959 +148,3540 @@ public class ArrayUtils {
     public static final int INDEX_NOT_FOUND = -1;
 
     /**
-     * <p>ArrayUtils instances should NOT be constructed in standard programming.
-     * Instead, the class should be used as <code>ArrayUtils.clone(new int[] {2})</code>.
+     * <p>Copies the given array and adds the given element at the end of the new array.
      *
-     * <p>This constructor is public to permit tools that require a JavaBean instance
-     * to operate.
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
+     *
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
+     *
+     * <pre>
+     * ArrayUtils.add(null, true)          = [true]
+     * ArrayUtils.add([true], false)       = [true, false]
+     * ArrayUtils.add([true, false], true) = [true, false, true]
+     * </pre>
+     *
+     * @param array  the array to copy and add the element to, may be {@code null}
+     * @param element  the object to add at the last index of the new array
+     * @return A new array containing the existing elements plus the new element
+     * @since 2.1
      */
-    public ArrayUtils() {
-      super();
+    public static boolean[] add(final boolean[] array, final boolean element) {
+        final boolean[] newArray = (boolean[]) copyArrayGrow1(array, Boolean.TYPE);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
 
     // NOTE: Cannot use {@code} to enclose text which includes {}, but <code></code> is OK
 
 
-    // Basic methods handling multi-dimensional arrays
-    //-----------------------------------------------------------------------
     /**
-     * <p>Outputs an array as a String, treating {@code null} as an empty array.
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <p>Multi-dimensional arrays are handled correctly, including
-     * multi-dimensional primitive arrays.
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * <p>The format is that of Java source code, for example <code>{a,b}</code>.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * @param array  the array to get a toString for, may be {@code null}
-     * @return a String representation of the array, '{}' if null array input
+     * <pre>
+     * ArrayUtils.add(null, 0, true)          = [true]
+     * ArrayUtils.add([true], 0, false)       = [false, true]
+     * ArrayUtils.add([false], 1, true)       = [false, true]
+     * ArrayUtils.add([true, false], 1, true) = [true, true, false]
+     * </pre>
+     *
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range (index &lt; 0 || index &gt; array.length).
+     * @deprecated this method has been superseded by {@link #insert(int, boolean[], boolean...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
-    public static String toString(final Object array) {
-        return toString(array, "{}");
+    @Deprecated
+    public static boolean[] add(final boolean[] array, final int index, final boolean element) {
+        return (boolean[]) add(array, index, Boolean.valueOf(element), Boolean.TYPE);
     }
 
     /**
-     * <p>Outputs an array as a String handling {@code null}s.
+     * <p>Copies the given array and adds the given element at the end of the new array.
      *
-     * <p>Multi-dimensional arrays are handled correctly, including
-     * multi-dimensional primitive arrays.
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
      *
-     * <p>The format is that of Java source code, for example <code>{a,b}</code>.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * @param array  the array to get a toString for, may be {@code null}
-     * @param stringIfNull  the String to return if the array is {@code null}
-     * @return a String representation of the array
+     * <pre>
+     * ArrayUtils.add(null, 0)   = [0]
+     * ArrayUtils.add([1], 0)    = [1, 0]
+     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * </pre>
+     *
+     * @param array  the array to copy and add the element to, may be {@code null}
+     * @param element  the object to add at the last index of the new array
+     * @return A new array containing the existing elements plus the new element
+     * @since 2.1
      */
-    public static String toString(final Object array, final String stringIfNull) {
-        if (array == null) {
-            return stringIfNull;
-        }
-        return new ToStringBuilder(array, ToStringStyle.SIMPLE_STYLE).append(array).toString();
+    public static byte[] add(final byte[] array, final byte element) {
+        final byte[] newArray = (byte[]) copyArrayGrow1(array, Byte.TYPE);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
     /**
-     * <p>Get a hash code for an array handling multi-dimensional arrays correctly.
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <p>Multi-dimensional primitive arrays are also handled correctly by this method.
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to get a hash code for, {@code null} returns zero
-     * @return a hash code for the array
-     */
-    public static int hashCode(final Object array) {
-        return new HashCodeBuilder().append(array).toHashCode();
-    }
-
-    /**
-     * <p>Compares two arrays, using equals(), handling multi-dimensional arrays
-     * correctly.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * <p>Multi-dimensional primitive arrays are also handled correctly by this method.
+     * <pre>
+     * ArrayUtils.add([1], 0, 2)         = [2, 1]
+     * ArrayUtils.add([2, 6], 2, 3)      = [2, 6, 3]
+     * ArrayUtils.add([2, 6], 0, 1)      = [1, 2, 6]
+     * ArrayUtils.add([2, 6, 3], 2, 1)   = [2, 6, 1, 3]
+     * </pre>
      *
-     * @param array1  the left hand array to compare, may be {@code null}
-     * @param array2  the right hand array to compare, may be {@code null}
-     * @return {@code true} if the arrays are equal
-     * @deprecated this method has been replaced by {@code java.util.Objects.deepEquals(Object, Object)} and will be
-     * removed from future releases.
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt; array.length).
+     * @deprecated this method has been superseded by {@link #insert(int, byte[], byte...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
     @Deprecated
-    public static boolean isEquals(final Object array1, final Object array2) {
-        return new EqualsBuilder().append(array1, array2).isEquals();
+    public static byte[] add(final byte[] array, final int index, final byte element) {
+        return (byte[]) add(array, index, Byte.valueOf(element), Byte.TYPE);
     }
 
-    // To map
-    //-----------------------------------------------------------------------
     /**
-     * <p>Converts the given array into a {@link java.util.Map}. Each element of the array
-     * must be either a {@link java.util.Map.Entry} or an Array, containing at least two
-     * elements, where the first element is used as key and the second as
-     * value.
+     * <p>Copies the given array and adds the given element at the end of the new array.
+     *
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
+     *
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * <p>This method can be used to initialize:
      * <pre>
-     * // Create a Map mapping colors.
-     * Map colorMap = ArrayUtils.toMap(new String[][] {
-     *     {"RED", "#FF0000"},
-     *     {"GREEN", "#00FF00"},
-     *     {"BLUE", "#0000FF"}});
+     * ArrayUtils.add(null, '0')       = ['0']
+     * ArrayUtils.add(['1'], '0')      = ['1', '0']
+     * ArrayUtils.add(['1', '0'], '1') = ['1', '0', '1']
      * </pre>
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
-     *
-     * @param array  an array whose elements are either a {@link java.util.Map.Entry} or
-     *  an Array containing at least two elements, may be {@code null}
-     * @return a {@code Map} that was created from the array
-     * @throws IllegalArgumentException  if one element of this Array is
-     *  itself an Array containing less then two elements
-     * @throws IllegalArgumentException  if the array contains elements other
-     *  than {@link java.util.Map.Entry} and an Array
+     * @param array  the array to copy and add the element to, may be {@code null}
+     * @param element  the object to add at the last index of the new array
+     * @return A new array containing the existing elements plus the new element
+     * @since 2.1
      */
-    public static Map<Object, Object> toMap(final Object[] array) {
-        if (array == null) {
-            return null;
-        }
-        final Map<Object, Object> map = new HashMap<>((int) (array.length * 1.5));
-        for (int i = 0; i < array.length; i++) {
-            final Object object = array[i];
-            if (object instanceof Map.Entry<?, ?>) {
-                final Map.Entry<?, ?> entry = (Map.Entry<?, ?>) object;
-                map.put(entry.getKey(), entry.getValue());
-            } else if (object instanceof Object[]) {
-                final Object[] entry = (Object[]) object;
-                if (entry.length < 2) {
-                    throw new IllegalArgumentException("Array element " + i + ", '"
-                        + object
-                        + "', has a length less than 2");
-                }
-                map.put(entry[0], entry[1]);
-            } else {
-                throw new IllegalArgumentException("Array element " + i + ", '"
-                        + object
-                        + "', is neither of type Map.Entry nor an Array");
-            }
-        }
-        return map;
+    public static char[] add(final char[] array, final char element) {
+        final char[] newArray = (char[]) copyArrayGrow1(array, Character.TYPE);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
-    // Generic array
-    //-----------------------------------------------------------------------
     /**
-     * <p>Create a type-safe generic array.
-     *
-     * <p>The Java language does not allow an array to be created from a generic type:
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <pre>
-    public static &lt;T&gt; T[] createAnArray(int size) {
-        return new T[size]; // compiler error here
-    }
-    public static &lt;T&gt; T[] createAnArray(int size) {
-        return (T[]) new Object[size]; // ClassCastException at runtime
-    }
-     * </pre>
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * <p>Therefore new arrays of generic types can be created with this method.
-     * For example, an array of Strings can be created:
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
      * <pre>
-    String[] array = ArrayUtils.toArray("1", "2");
-    String[] emptyArray = ArrayUtils.&lt;String&gt;toArray();
+     * ArrayUtils.add(null, 0, 'a')            = ['a']
+     * ArrayUtils.add(['a'], 0, 'b')           = ['b', 'a']
+     * ArrayUtils.add(['a', 'b'], 0, 'c')      = ['c', 'a', 'b']
+     * ArrayUtils.add(['a', 'b'], 1, 'k')      = ['a', 'k', 'b']
+     * ArrayUtils.add(['a', 'b', 'c'], 1, 't') = ['a', 't', 'b', 'c']
      * </pre>
      *
-     * <p>The method is typically used in scenarios, where the caller itself uses generic types
-     * that have to be combined into an array.
-     *
-     * <p>Note, this method makes only sense to provide arguments of the same type so that the
-     * compiler can deduce the type of the array itself. While it is possible to select the
-     * type explicitly like in
-     * <code>Number[] array = ArrayUtils.&lt;Number&gt;toArray(Integer.valueOf(42), Double.valueOf(Math.PI))</code>,
-     * there is no real advantage when compared to
-     * <code>new Number[] {Integer.valueOf(42), Double.valueOf(Math.PI)}</code>.
-     *
-     * @param  <T>   the array's element type
-     * @param  items  the varargs array items, null allowed
-     * @return the array, not null unless a null array is passed in
-     * @since  3.0
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt; array.length).
+     * @deprecated this method has been superseded by {@link #insert(int, char[], char...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
-    public static <T> T[] toArray(@SuppressWarnings("unchecked") final T... items) {
-        return items;
+    @Deprecated
+    public static char[] add(final char[] array, final int index, final char element) {
+        return (char[]) add(array, index, Character.valueOf(element), Character.TYPE);
     }
 
-    // Clone
-    //-----------------------------------------------------------------------
     /**
-     * <p>Shallow clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>Copies the given array and adds the given element at the end of the new array.
      *
-     * <p>The objects in the array are not cloned, thus there is no special
-     * handling for multi-dimensional arrays.
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * @param <T> the component type of the array
-     * @param array  the array to shallow clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
+     * <pre>
+     * ArrayUtils.add(null, 0)   = [0]
+     * ArrayUtils.add([1], 0)    = [1, 0]
+     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * </pre>
+     *
+     * @param array  the array to copy and add the element to, may be {@code null}
+     * @param element  the object to add at the last index of the new array
+     * @return A new array containing the existing elements plus the new element
+     * @since 2.1
      */
-    public static <T> T[] clone(final T[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
+    public static double[] add(final double[] array, final double element) {
+        final double[] newArray = (double[]) copyArrayGrow1(array, Double.TYPE);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
     /**
-     * <p>Clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
-     */
-    public static long[] clone(final long[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
-    }
-
-    /**
-     * <p>Clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <pre>
+     * ArrayUtils.add([1.1], 0, 2.2)              = [2.2, 1.1]
+     * ArrayUtils.add([2.3, 6.4], 2, 10.5)        = [2.3, 6.4, 10.5]
+     * ArrayUtils.add([2.6, 6.7], 0, -4.8)        = [-4.8, 2.6, 6.7]
+     * ArrayUtils.add([2.9, 6.0, 0.3], 2, 1.0)    = [2.9, 6.0, 1.0, 0.3]
+     * </pre>
      *
-     * @param array  the array to clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt; array.length).
+     * @deprecated this method has been superseded by {@link #insert(int, double[], double...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
-    public static int[] clone(final int[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
+    @Deprecated
+    public static double[] add(final double[] array, final int index, final double element) {
+        return (double[]) add(array, index, Double.valueOf(element), Double.TYPE);
     }
 
     /**
-     * <p>Clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>Copies the given array and adds the given element at the end of the new array.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
      *
-     * @param array  the array to clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
-     */
-    public static short[] clone(final short[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
-    }
-
-    /**
-     * <p>Clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <pre>
+     * ArrayUtils.add(null, 0)   = [0]
+     * ArrayUtils.add([1], 0)    = [1, 0]
+     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * </pre>
      *
-     * @param array  the array to clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
+     * @param array  the array to copy and add the element to, may be {@code null}
+     * @param element  the object to add at the last index of the new array
+     * @return A new array containing the existing elements plus the new element
+     * @since 2.1
      */
-    public static char[] clone(final char[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
+    public static float[] add(final float[] array, final float element) {
+        final float[] newArray = (float[]) copyArrayGrow1(array, Float.TYPE);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
     /**
-     * <p>Clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
+     *
+     * <pre>
+     * ArrayUtils.add([1.1f], 0, 2.2f)               = [2.2f, 1.1f]
+     * ArrayUtils.add([2.3f, 6.4f], 2, 10.5f)        = [2.3f, 6.4f, 10.5f]
+     * ArrayUtils.add([2.6f, 6.7f], 0, -4.8f)        = [-4.8f, 2.6f, 6.7f]
+     * ArrayUtils.add([2.9f, 6.0f, 0.3f], 2, 1.0f)   = [2.9f, 6.0f, 1.0f, 0.3f]
+     * </pre>
+     *
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt; array.length).
+     * @deprecated this method has been superseded by {@link #insert(int, float[], float...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
-    public static byte[] clone(final byte[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
+    @Deprecated
+    public static float[] add(final float[] array, final int index, final float element) {
+        return (float[]) add(array, index, Float.valueOf(element), Float.TYPE);
     }
 
     /**
-     * <p>Clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>Copies the given array and adds the given element at the end of the new array.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
      *
-     * @param array  the array to clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
-     */
-    public static double[] clone(final double[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
-    }
-
-    /**
-     * <p>Clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <pre>
+     * ArrayUtils.add(null, 0)   = [0]
+     * ArrayUtils.add([1], 0)    = [1, 0]
+     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * </pre>
      *
-     * @param array  the array to clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
+     * @param array  the array to copy and add the element to, may be {@code null}
+     * @param element  the object to add at the last index of the new array
+     * @return A new array containing the existing elements plus the new element
+     * @since 2.1
      */
-    public static float[] clone(final float[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
+    public static int[] add(final int[] array, final int element) {
+        final int[] newArray = (int[]) copyArrayGrow1(array, Integer.TYPE);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
     /**
-     * <p>Clones an array returning a typecast result and handling
-     * {@code null}.
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to clone, may be {@code null}
-     * @return the cloned array, {@code null} if {@code null} input
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
+     *
+     * <pre>
+     * ArrayUtils.add([1], 0, 2)         = [2, 1]
+     * ArrayUtils.add([2, 6], 2, 10)     = [2, 6, 10]
+     * ArrayUtils.add([2, 6], 0, -4)     = [-4, 2, 6]
+     * ArrayUtils.add([2, 6, 3], 2, 1)   = [2, 6, 1, 3]
+     * </pre>
+     *
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt; array.length).
+     * @deprecated this method has been superseded by {@link #insert(int, int[], int...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
-    public static boolean[] clone(final boolean[] array) {
-        if (array == null) {
-            return null;
-        }
-        return array.clone();
+    @Deprecated
+    public static int[] add(final int[] array, final int index, final int element) {
+        return (int[]) add(array, index, Integer.valueOf(element), Integer.TYPE);
     }
 
-    // nullToEmpty
-    //-----------------------------------------------------------------------
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to check for {@code null} or empty
-     * @param type   the class representation of the desired array
-     * @param <T>  the class type
-     * @return the same array, {@code public static} empty array if {@code null}
-     * @throws IllegalArgumentException if the type argument is null
-     * @since 3.5
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
+     *
+     * <pre>
+     * ArrayUtils.add([1L], 0, 2L)           = [2L, 1L]
+     * ArrayUtils.add([2L, 6L], 2, 10L)      = [2L, 6L, 10L]
+     * ArrayUtils.add([2L, 6L], 0, -4L)      = [-4L, 2L, 6L]
+     * ArrayUtils.add([2L, 6L, 3L], 2, 1L)   = [2L, 6L, 1L, 3L]
+     * </pre>
+     *
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt; array.length).
+     * @deprecated this method has been superseded by {@link #insert(int, long[], long...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
-    public static <T> T[] nullToEmpty(final T[] array, final Class<T[]> type) {
-        if (type == null) {
-            throw new IllegalArgumentException("The type must not be null");
-        }
-
-        if (array == null) {
-            return type.cast(Array.newInstance(type.getComponentType(), 0));
-        }
-        return array;
+    @Deprecated
+    public static long[] add(final long[] array, final int index, final long element) {
+        return (long[]) add(array, index, Long.valueOf(element), Long.TYPE);
     }
 
-
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
+     * <p>Copies the given array and adds the given element at the end of the new array.
      *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * <pre>
+     * ArrayUtils.add(null, 0)   = [0]
+     * ArrayUtils.add([1], 0)    = [1, 0]
+     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * </pre>
+     *
+     * @param array  the array to copy and add the element to, may be {@code null}
+     * @param element  the object to add at the last index of the new array
+     * @return A new array containing the existing elements plus the new element
+     * @since 2.1
      */
-    public static Object[] nullToEmpty(final Object[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_OBJECT_ARRAY;
-        }
-        return array;
+    public static long[] add(final long[] array, final long element) {
+        final long[] newArray = (long[]) copyArrayGrow1(array, Long.TYPE);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
-     *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * Underlying implementation of add(array, index, element) methods.
+     * The last parameter is the class, which may not equal element.getClass
+     * for primitives.
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 3.2
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @param clss the type of the element being added
+     * @return A new array containing the existing elements and the new element
      */
-    public static Class<?>[] nullToEmpty(final Class<?>[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_CLASS_ARRAY;
+    private static Object add(final Object array, final int index, final Object element, final Class<?> clss) {
+        if (array == null) {
+            if (index != 0) {
+                throw new IndexOutOfBoundsException("Index: " + index + ", Length: 0");
+            }
+            final Object joinedArray = Array.newInstance(clss, 1);
+            Array.set(joinedArray, 0, element);
+            return joinedArray;
         }
-        return array;
+        final int length = Array.getLength(array);
+        if (index > length || index < 0) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + length);
+        }
+        final Object result = Array.newInstance(clss, length + 1);
+        System.arraycopy(array, 0, result, 0, index);
+        Array.set(result, index, element);
+        if (index < length) {
+            System.arraycopy(array, index, result, index + 1, length - index);
+        }
+        return result;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * <pre>
+     * ArrayUtils.add([1], 0, 2)         = [2, 1]
+     * ArrayUtils.add([2, 6], 2, 10)     = [2, 6, 10]
+     * ArrayUtils.add([2, 6], 0, -4)     = [-4, 2, 6]
+     * ArrayUtils.add([2, 6, 3], 2, 1)   = [2, 6, 1, 3]
+     * </pre>
+     *
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt; array.length).
+     * @deprecated this method has been superseded by {@link #insert(int, short[], short...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
-    public static String[] nullToEmpty(final String[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_STRING_ARRAY;
-        }
-        return array;
+    @Deprecated
+    public static short[] add(final short[] array, final int index, final short element) {
+        return (short[]) add(array, index, Short.valueOf(element), Short.TYPE);
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Copies the given array and adds the given element at the end of the new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
-     */
-    public static long[] nullToEmpty(final long[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_LONG_ARRAY;
-        }
-        return array;
-    }
-
-    /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.add(null, 0)   = [0]
+     * ArrayUtils.add([1], 0)    = [1, 0]
+     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array  the array to copy and add the element to, may be {@code null}
+     * @param element  the object to add at the last index of the new array
+     * @return A new array containing the existing elements plus the new element
+     * @since 2.1
      */
-    public static int[] nullToEmpty(final int[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_INT_ARRAY;
-        }
-        return array;
+    public static short[] add(final short[] array, final short element) {
+        final short[] newArray = (short[]) copyArrayGrow1(array, Short.TYPE);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
+
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
+     * <p>Inserts the specified element at the specified position in the array.
+     * Shifts the element currently at that position (if any) and any subsequent
+     * elements to the right (adds one to their indices).
      *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array plus the given element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element.
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * <pre>
+     * ArrayUtils.add(null, 0, null)      = IllegalArgumentException
+     * ArrayUtils.add(null, 0, "a")       = ["a"]
+     * ArrayUtils.add(["a"], 1, null)     = ["a", null]
+     * ArrayUtils.add(["a"], 1, "b")      = ["a", "b"]
+     * ArrayUtils.add(["a", "b"], 3, "c") = ["a", "b", "c"]
+     * </pre>
+     *
+     * @param <T> the component type of the array
+     * @param array  the array to add the element to, may be {@code null}
+     * @param index  the position of the new object
+     * @param element  the object to add
+     * @return A new array containing the existing elements and the new element
+     * @throws IndexOutOfBoundsException if the index is out of range (index &lt; 0 || index &gt; array.length).
+     * @throws IllegalArgumentException if both array and element are null
+     * @deprecated this method has been superseded by {@link #insert(int, Object[], Object...) insert(int, T[], T...)} and
+     * may be removed in a future release. Please note the handling of {@code null} input arrays differs
+     * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}.
      */
-    public static short[] nullToEmpty(final short[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_SHORT_ARRAY;
+    @Deprecated
+    public static <T> T[] add(final T[] array, final int index, final T element) {
+        Class<?> clss = null;
+        if (array != null) {
+            clss = array.getClass().getComponentType();
+        } else if (element != null) {
+            clss = element.getClass();
+        } else {
+            throw new IllegalArgumentException("Array and element cannot both be null");
         }
-        return array;
+        @SuppressWarnings("unchecked") // the add method creates an array of type clss, which is type T
+        final T[] newArray = (T[]) add(array, index, element, clss);
+        return newArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
+     * <p>Copies the given array and adds the given element at the end of the new array.
      *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>The new array contains the same elements of the input
+     * array plus the given element in the last position. The component type of
+     * the new array is the same as that of the input array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <p>If the input array is {@code null}, a new one element array is returned
+     *  whose component type is the same as the element, unless the element itself is null,
+     *  in which case the return type is Object[]
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * <pre>
+     * ArrayUtils.add(null, null)      = IllegalArgumentException
+     * ArrayUtils.add(null, "a")       = ["a"]
+     * ArrayUtils.add(["a"], null)     = ["a", null]
+     * ArrayUtils.add(["a"], "b")      = ["a", "b"]
+     * ArrayUtils.add(["a", "b"], "c") = ["a", "b", "c"]
+     * </pre>
+     *
+     * @param <T> the component type of the array
+     * @param array  the array to "add" the element to, may be {@code null}
+     * @param element  the object to add, may be {@code null}
+     * @return A new array containing the existing elements plus the new element
+     * The returned array type will be that of the input array (unless null),
+     * in which case it will have the same type as the element.
+     * If both are null, an IllegalArgumentException is thrown
+     * @since 2.1
+     * @throws IllegalArgumentException if both arguments are null
      */
-    public static char[] nullToEmpty(final char[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_CHAR_ARRAY;
+    public static <T> T[] add(final T[] array, final T element) {
+        Class<?> type;
+        if (array != null) {
+            type = array.getClass().getComponentType();
+        } else if (element != null) {
+            type = element.getClass();
+        } else {
+            throw new IllegalArgumentException("Arguments cannot both be null");
         }
-        return array;
+        @SuppressWarnings("unchecked") // type must be T
+        final
+        T[] newArray = (T[]) copyArrayGrow1(array, type);
+        newArray[newArray.length - 1] = element;
+        return newArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array1  the first array whose elements are added to the new array.
+     * @param array2  the second array whose elements are added to the new array.
+     * @return The new boolean[] array.
+     * @since 2.1
      */
-    public static byte[] nullToEmpty(final byte[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_BYTE_ARRAY;
+    public static boolean[] addAll(final boolean[] array1, final boolean... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final boolean[] joinedArray = new boolean[array1.length + array2.length];
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array1  the first array whose elements are added to the new array.
+     * @param array2  the second array whose elements are added to the new array.
+     * @return The new byte[] array.
+     * @since 2.1
      */
-    public static double[] nullToEmpty(final double[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_DOUBLE_ARRAY;
+    public static byte[] addAll(final byte[] array1, final byte... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final byte[] joinedArray = new byte[array1.length + array2.length];
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array1  the first array whose elements are added to the new array.
+     * @param array2  the second array whose elements are added to the new array.
+     * @return The new char[] array.
+     * @since 2.1
      */
-    public static float[] nullToEmpty(final float[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_FLOAT_ARRAY;
+    public static char[] addAll(final char[] array1, final char... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final char[] joinedArray = new char[array1.length + array2.length];
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array1  the first array whose elements are added to the new array.
+     * @param array2  the second array whose elements are added to the new array.
+     * @return The new double[] array.
+     * @since 2.1
      */
-    public static boolean[] nullToEmpty(final boolean[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_BOOLEAN_ARRAY;
+    public static double[] addAll(final double[] array1, final double... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final double[] joinedArray = new double[array1.length + array2.length];
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array1  the first array whose elements are added to the new array.
+     * @param array2  the second array whose elements are added to the new array.
+     * @return The new float[] array.
+     * @since 2.1
      */
-    public static Long[] nullToEmpty(final Long[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_LONG_OBJECT_ARRAY;
+    public static float[] addAll(final float[] array1, final float... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final float[] joinedArray = new float[array1.length + array2.length];
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array1  the first array whose elements are added to the new array.
+     * @param array2  the second array whose elements are added to the new array.
+     * @return The new int[] array.
+     * @since 2.1
      */
-    public static Integer[] nullToEmpty(final Integer[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_INTEGER_OBJECT_ARRAY;
+    public static int[] addAll(final int[] array1, final int... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final int[] joinedArray = new int[array1.length + array2.length];
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array1  the first array whose elements are added to the new array.
+     * @param array2  the second array whose elements are added to the new array.
+     * @return The new long[] array.
+     * @since 2.1
      */
-    public static Short[] nullToEmpty(final Short[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_SHORT_OBJECT_ARRAY;
+    public static long[] addAll(final long[] array1, final long... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final long[] joinedArray = new long[array1.length + array2.length];
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param array1  the first array whose elements are added to the new array.
+     * @param array2  the second array whose elements are added to the new array.
+     * @return The new short[] array.
+     * @since 2.1
      */
-    public static Character[] nullToEmpty(final Character[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_CHARACTER_OBJECT_ARRAY;
+    public static short[] addAll(final short[] array1, final short... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final short[] joinedArray = new short[array1.length + array2.length];
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
-     *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>Adds all the elements of the given arrays into a new array.
+     * <p>The new array contains all of the element of {@code array1} followed
+     * by all of the elements {@code array2}. When an array is returned, it is always
+     * a new array.
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <pre>
+     * ArrayUtils.addAll(null, null)     = null
+     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
+     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
+     * ArrayUtils.addAll([], [])         = []
+     * ArrayUtils.addAll([null], [null]) = [null, null]
+     * ArrayUtils.addAll(["a", "b", "c"], ["1", "2", "3"]) = ["a", "b", "c", "1", "2", "3"]
+     * </pre>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * @param <T> the component type of the array
+     * @param array1  the first array whose elements are added to the new array, may be {@code null}
+     * @param array2  the second array whose elements are added to the new array, may be {@code null}
+     * @return The new array, {@code null} if both arrays are {@code null}.
+     *      The type of the new array is the type of the first array,
+     *      unless the first array is null, in which case the type is the same as the second array.
+     * @since 2.1
+     * @throws IllegalArgumentException if the array types are incompatible
      */
-    public static Byte[] nullToEmpty(final Byte[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_BYTE_OBJECT_ARRAY;
+    public static <T> T[] addAll(final T[] array1, @SuppressWarnings("unchecked") final T... array2) {
+        if (array1 == null) {
+            return clone(array2);
+        } else if (array2 == null) {
+            return clone(array1);
         }
-        return array;
+        final Class<?> type1 = array1.getClass().getComponentType();
+        @SuppressWarnings("unchecked") // OK, because array is of type T
+        final T[] joinedArray = (T[]) Array.newInstance(type1, array1.length + array2.length);
+        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
+        try {
+            System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
+        } catch (final ArrayStoreException ase) {
+            // Check if problem was due to incompatible types
+            /*
+             * We do this here, rather than before the copy because:
+             * - it would be a wasted check most of the time
+             * - safer, in case check turns out to be too strict
+             */
+            final Class<?> type2 = array2.getClass().getComponentType();
+            if (!type1.isAssignableFrom(type2)) {
+                throw new IllegalArgumentException("Cannot store " + type2.getName() + " in an array of "
+                        + type1.getName(), ase);
+            }
+            throw ase; // No, so rethrow original
+        }
+        return joinedArray;
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
+     * Copies the given array and adds the given element at the beginning of the new array.
      *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first position. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element.
+     * </p>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * <pre>
+     * ArrayUtils.add(null, true)          = [true]
+     * ArrayUtils.add([true], false)       = [false, true]
+     * ArrayUtils.add([true, false], true) = [true, true, false]
+     * </pre>
+     *
+     * @param array the array to "add" the element to, may be {@code null}.
+     * @param element the object to add.
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element.
+     * @since 3.10
      */
-    public static Double[] nullToEmpty(final Double[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_DOUBLE_OBJECT_ARRAY;
-        }
-        return array;
+    public static boolean[] addFirst(final boolean[] array, final boolean element) {
+        return array == null ? add(array, element) : insert(0, array, element);
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
+     * Copies the given array and adds the given element at the beginning of the new array.
      *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first position. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element.
+     * </p>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * <pre>
+     * ArrayUtils.add(null, 1)   = [1]
+     * ArrayUtils.add([1], 0)    = [0, 1]
+     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
+     * </pre>
+     *
+     * @param array the array to "add" the element to, may be {@code null}.
+     * @param element the object to add.
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element.
+     * @since 3.10
      */
-    public static Float[] nullToEmpty(final Float[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_FLOAT_OBJECT_ARRAY;
-        }
-        return array;
+    public static byte[] addFirst(final byte[] array, final byte element) {
+        return array == null ? add(array, element) : insert(0, array, element);
     }
 
     /**
-     * <p>Defensive programming technique to change a {@code null}
-     * reference to an empty one.
+     * Copies the given array and adds the given element at the beginning of the new array.
      *
-     * <p>This method returns an empty array for a {@code null} input array.
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first position. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
      *
-     * <p>As a memory optimizing technique an empty array passed in will be overridden with
-     * the empty {@code public static} references in this class.
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element.
+     * </p>
      *
-     * @param array  the array to check for {@code null} or empty
-     * @return the same array, {@code public static} empty array if {@code null} or empty input
-     * @since 2.5
+     * <pre>
+     * ArrayUtils.add(null, '1')       = ['1']
+     * ArrayUtils.add(['1'], '0')      = ['0', '1']
+     * ArrayUtils.add(['1', '0'], '1') = ['1', '1', '0']
+     * </pre>
+     *
+     * @param array the array to "add" the element to, may be {@code null}.
+     * @param element the object to add.
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element.
+     * @since 3.10
      */
-    public static Boolean[] nullToEmpty(final Boolean[] array) {
-        if (isEmpty(array)) {
-            return EMPTY_BOOLEAN_OBJECT_ARRAY;
-        }
-        return array;
+    public static char[] addFirst(final char[] array, final char element) {
+        return array == null ? add(array, element) : insert(0, array, element);
     }
 
-    // Subarrays
-    //-----------------------------------------------------------------------
     /**
-     * <p>Produces a new array containing the elements between
-     * the start and end indices.
+     * Copies the given array and adds the given element at the beginning of the new array.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first position. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
      *
-     * <p>The component type of the subarray is always the same as
-     * that of the input array. Thus, if the input is an array of type
-     * {@code Date}, the following usage is envisaged:
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element.
+     * </p>
      *
      * <pre>
-     * Date[] someDates = (Date[]) ArrayUtils.subarray(allDates, 2, 5);
+     * ArrayUtils.add(null, 1)   = [1]
+     * ArrayUtils.add([1], 0)    = [0, 1]
+     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
      * </pre>
      *
-     * @param <T> the component type of the array
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(Object[], int, int)
+     * @param array the array to "add" the element to, may be {@code null}.
+     * @param element the object to add.
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element.
+     * @since 3.10
      */
-    public static <T> T[] subarray(final T[] array, int startIndexInclusive, int endIndexExclusive) {
-        if (array == null) {
-            return null;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        final Class<?> type = array.getClass().getComponentType();
-        if (newSize <= 0) {
-            @SuppressWarnings("unchecked") // OK, because array is of type T
-            final T[] emptyArray = (T[]) Array.newInstance(type, 0);
-            return emptyArray;
-        }
-        @SuppressWarnings("unchecked") // OK, because array is of type T
-        final
-        T[] subarray = (T[]) Array.newInstance(type, newSize);
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+    public static double[] addFirst(final double[] array, final double element) {
+        return array == null ? add(array, element) : insert(0, array, element);
     }
 
     /**
-     * <p>Produces a new {@code long} array containing the elements
-     * between the start and end indices.
+     * Copies the given array and adds the given element at the beginning of the new array.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first position. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
      *
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(long[], int, int)
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element.
+     * </p>
+     *
+     * <pre>
+     * ArrayUtils.add(null, 1)   = [1]
+     * ArrayUtils.add([1], 0)    = [0, 1]
+     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
+     * </pre>
+     *
+     * @param array the array to "add" the element to, may be {@code null}.
+     * @param element the object to add.
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element.
+     * @since 3.10
      */
-    public static long[] subarray(final long[] array, int startIndexInclusive, int endIndexExclusive) {
-        if (array == null) {
-            return null;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        if (newSize <= 0) {
-            return EMPTY_LONG_ARRAY;
-        }
-
-        final long[] subarray = new long[newSize];
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+    public static float[] addFirst(final float[] array, final float element) {
+        return array == null ? add(array, element) : insert(0, array, element);
     }
 
     /**
-     * <p>Produces a new {@code int} array containing the elements
-     * between the start and end indices.
+     * Copies the given array and adds the given element at the beginning of the new array.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first position. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
      *
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(int[], int, int)
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element.
+     * </p>
+     *
+     * <pre>
+     * ArrayUtils.add(null, 1)   = [1]
+     * ArrayUtils.add([1], 0)    = [0, 1]
+     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
+     * </pre>
+     *
+     * @param array the array to "add" the element to, may be {@code null}.
+     * @param element the object to add.
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element.
+     * @since 3.10
      */
-    public static int[] subarray(final int[] array, int startIndexInclusive, int endIndexExclusive) {
-        if (array == null) {
-            return null;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        if (newSize <= 0) {
-            return EMPTY_INT_ARRAY;
-        }
-
-        final int[] subarray = new int[newSize];
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+    public static int[] addFirst(final int[] array, final int element) {
+        return array == null ? add(array, element) : insert(0, array, element);
     }
 
     /**
-     * <p>Produces a new {@code short} array containing the elements
-     * between the start and end indices.
+     * Copies the given array and adds the given element at the beginning of the new array.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first position. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
      *
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(short[], int, int)
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element.
+     * </p>
+     *
+     * <pre>
+     * ArrayUtils.add(null, 1)   = [1]
+     * ArrayUtils.add([1], 0)    = [0, 1]
+     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
+     * </pre>
+     *
+     * @param array the array to "add" the element to, may be {@code null}.
+     * @param element the object to add.
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element.
+     * @since 3.10
      */
-    public static short[] subarray(final short[] array, int startIndexInclusive, int endIndexExclusive) {
-        if (array == null) {
-            return null;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        if (newSize <= 0) {
-            return EMPTY_SHORT_ARRAY;
-        }
-
-        final short[] subarray = new short[newSize];
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+    public static long[] addFirst(final long[] array, final long element) {
+        return array == null ? add(array, element) : insert(0, array, element);
     }
 
     /**
-     * <p>Produces a new {@code char} array containing the elements
-     * between the start and end indices.
+     * Copies the given array and adds the given element at the beginning of the new array.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first position. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
      *
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(char[], int, int)
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element.
+     * </p>
+     *
+     * <pre>
+     * ArrayUtils.add(null, 1)   = [1]
+     * ArrayUtils.add([1], 0)    = [0, 1]
+     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
+     * </pre>
+     *
+     * @param array the array to "add" the element to, may be {@code null}.
+     * @param element the object to add.
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element.
+     * @since 3.10
      */
-    public static char[] subarray(final char[] array, int startIndexInclusive, int endIndexExclusive) {
-        if (array == null) {
-            return null;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        if (newSize <= 0) {
-            return EMPTY_CHAR_ARRAY;
-        }
+    public static short[] addFirst(final short[] array, final short element) {
+        return array == null ? add(array, element) : insert(0, array, element);
+    }
 
-        final char[] subarray = new char[newSize];
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+    /**
+     * Copies the given array and adds the given element at the beginning of the new array.
+     *
+     * <p>
+     * The new array contains the same elements of the input array plus the given element in the first positioaddFirstaddFirstaddFirstn. The
+     * component type of the new array is the same as that of the input array.
+     * </p>
+     *
+     * <p>
+     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
+     * element, unless the element itself is null, in which case the return type is Object[]
+     * </p>
+     *
+     * <pre>
+     * ArrayUtils.add(null, null)      = IllegalArgumentException
+     * ArrayUtils.add(null, "a")       = ["a"]
+     * ArrayUtils.add(["a"], null)     = [null, "a"]
+     * ArrayUtils.add(["a"], "b")      = ["b", "a"]
+     * ArrayUtils.add(["a", "b"], "c") = ["c", "a", "b"]
+     * </pre>
+     *
+     * @param <T> the component type of the array
+     * @param array the array to "add" the element to, may be {@code null}
+     * @param element the object to add, may be {@code null}
+     * @return A new array containing the existing elements plus the new element The returned array type will be that of
+     *         the input array (unless null), in which case it will have the same type as the element. If both are null,
+     *         an IllegalArgumentException is thrown
+     * @since 3.10
+     * @throws IllegalArgumentException if both arguments are null
+     */
+    public static <T> T[] addFirst(final T[] array, final T element) {
+        return array == null ? add(array, element) : insert(0, array, element);
     }
 
     /**
-     * <p>Produces a new {@code byte} array containing the elements
-     * between the start and end indices.
+     * <p>Clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>This method returns {@code null} for a {@code null} input array.
      *
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(byte[], int, int)
+     * @param array  the array to clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static byte[] subarray(final byte[] array, int startIndexInclusive, int endIndexExclusive) {
+    public static boolean[] clone(final boolean[] array) {
         if (array == null) {
             return null;
         }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        if (newSize <= 0) {
-            return EMPTY_BYTE_ARRAY;
-        }
-
-        final byte[] subarray = new byte[newSize];
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+        return array.clone();
     }
 
     /**
-     * <p>Produces a new {@code double} array containing the elements
-     * between the start and end indices.
+     * <p>Clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>This method returns {@code null} for a {@code null} input array.
      *
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(double[], int, int)
+     * @param array  the array to clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static double[] subarray(final double[] array, int startIndexInclusive, int endIndexExclusive) {
+    public static byte[] clone(final byte[] array) {
         if (array == null) {
             return null;
         }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        if (newSize <= 0) {
-            return EMPTY_DOUBLE_ARRAY;
-        }
-
-        final double[] subarray = new double[newSize];
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+        return array.clone();
     }
 
     /**
-     * <p>Produces a new {@code float} array containing the elements
-     * between the start and end indices.
+     * <p>Clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>This method returns {@code null} for a {@code null} input array.
      *
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(float[], int, int)
+     * @param array  the array to clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static float[] subarray(final float[] array, int startIndexInclusive, int endIndexExclusive) {
+    public static char[] clone(final char[] array) {
         if (array == null) {
             return null;
         }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        if (newSize <= 0) {
-            return EMPTY_FLOAT_ARRAY;
-        }
-
-        final float[] subarray = new float[newSize];
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+        return array.clone();
     }
 
     /**
-     * <p>Produces a new {@code boolean} array containing the elements
-     * between the start and end indices.
+     * <p>Clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * <p>The start index is inclusive, the end index exclusive.
-     * Null array input produces null output.
+     * <p>This method returns {@code null} for a {@code null} input array.
      *
-     * @param array  the array
-     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
-     *      is promoted to 0, overvalue (&gt;array.length) results
-     *      in an empty array.
-     * @param endIndexExclusive  elements up to endIndex-1 are present in the
-     *      returned subarray. Undervalue (&lt; startIndex) produces
-     *      empty array, overvalue (&gt;array.length) is demoted to
-     *      array length.
-     * @return a new array containing the elements between
-     *      the start and end indices.
-     * @since 2.1
-     * @see Arrays#copyOfRange(boolean[], int, int)
+     * @param array  the array to clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static boolean[] subarray(final boolean[] array, int startIndexInclusive, int endIndexExclusive) {
+    public static double[] clone(final double[] array) {
         if (array == null) {
             return null;
         }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive > array.length) {
-            endIndexExclusive = array.length;
-        }
-        final int newSize = endIndexExclusive - startIndexInclusive;
-        if (newSize <= 0) {
-            return EMPTY_BOOLEAN_ARRAY;
-        }
-
-        final boolean[] subarray = new boolean[newSize];
-        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
-        return subarray;
+        return array.clone();
     }
 
-    // Is same length
-    //-----------------------------------------------------------------------
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * <p>Any multi-dimensional aspects of the arrays are ignored.
+     * <p>This method returns {@code null} for a {@code null} input array.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * @param array  the array to clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static boolean isSameLength(final Object[] array1, final Object[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static float[] clone(final float[] array) {
+        if (array == null) {
+            return null;
+        }
+        return array.clone();
     }
 
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * <p>This method returns {@code null} for a {@code null} input array.
+     *
+     * @param array  the array to clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static boolean isSameLength(final long[] array1, final long[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static int[] clone(final int[] array) {
+        if (array == null) {
+            return null;
+        }
+        return array.clone();
     }
 
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * <p>This method returns {@code null} for a {@code null} input array.
+     *
+     * @param array  the array to clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static boolean isSameLength(final int[] array1, final int[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static long[] clone(final long[] array) {
+        if (array == null) {
+            return null;
+        }
+        return array.clone();
     }
 
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * <p>This method returns {@code null} for a {@code null} input array.
+     *
+     * @param array  the array to clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static boolean isSameLength(final short[] array1, final short[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static short[] clone(final short[] array) {
+        if (array == null) {
+            return null;
+        }
+        return array.clone();
     }
 
+    // Clone
+    //-----------------------------------------------------------------------
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Shallow clones an array returning a typecast result and handling
+     * {@code null}.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * <p>The objects in the array are not cloned, thus there is no special
+     * handling for multi-dimensional arrays.
+     *
+     * <p>This method returns {@code null} for a {@code null} input array.
+     *
+     * @param <T> the component type of the array
+     * @param array  the array to shallow clone, may be {@code null}
+     * @return the cloned array, {@code null} if {@code null} input
      */
-    public static boolean isSameLength(final char[] array1, final char[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static <T> T[] clone(final T[] array) {
+        if (array == null) {
+            return null;
+        }
+        return array.clone();
     }
 
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Checks if the value is in the given array.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     *
+     * @param array  the array to search through
+     * @param valueToFind  the value to find
+     * @return {@code true} if the array contains the object
      */
-    public static boolean isSameLength(final byte[] array1, final byte[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static boolean contains(final boolean[] array, final boolean valueToFind) {
+        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
     }
 
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Checks if the value is in the given array.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     *
+     * @param array  the array to search through
+     * @param valueToFind  the value to find
+     * @return {@code true} if the array contains the object
      */
-    public static boolean isSameLength(final double[] array1, final double[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static boolean contains(final byte[] array, final byte valueToFind) {
+        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
     }
 
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Checks if the value is in the given array.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     *
+     * @param array  the array to search through
+     * @param valueToFind  the value to find
+     * @return {@code true} if the array contains the object
+     * @since 2.1
      */
-    public static boolean isSameLength(final float[] array1, final float[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static boolean contains(final char[] array, final char valueToFind) {
+        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
     }
 
     /**
-     * <p>Checks whether two arrays are the same length, treating
-     * {@code null} arrays as length {@code 0}.
+     * <p>Checks if the value is in the given array.
      *
-     * @param array1 the first array, may be {@code null}
-     * @param array2 the second array, may be {@code null}
-     * @return {@code true} if length of arrays matches, treating
-     *  {@code null} as an empty array
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     *
+     * @param array  the array to search through
+     * @param valueToFind  the value to find
+     * @return {@code true} if the array contains the object
      */
-    public static boolean isSameLength(final boolean[] array1, final boolean[] array2) {
-        return getLength(array1) == getLength(array2);
+    public static boolean contains(final double[] array, final double valueToFind) {
+        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
     }
 
-    //-----------------------------------------------------------------------
     /**
-     * <p>Returns the length of the specified array.
-     * This method can deal with {@code Object} arrays and with primitive arrays.
-     *
-     * <p>If the input array is {@code null}, {@code 0} is returned.
+     * <p>Checks if a value falling within the given tolerance is in the
+     * given array.  If the array contains a value within the inclusive range
+     * defined by (value - tolerance) to (value + tolerance).
      *
-     * <pre>
-     * ArrayUtils.getLength(null)            = 0
-     * ArrayUtils.getLength([])              = 0
-     * ArrayUtils.getLength([null])          = 1
-     * ArrayUtils.getLength([true, false])   = 2
-     * ArrayUtils.getLength([1, 2, 3])       = 3
-     * ArrayUtils.getLength(["a", "b", "c"]) = 3
-     * </pre>
+     * <p>The method returns {@code false} if a {@code null} array
+     * is passed in.
      *
-     * @param array  the array to retrieve the length from, may be null
-     * @return The length of the array, or {@code 0} if the array is {@code null}
-     * @throws IllegalArgumentException if the object argument is not an array.
-     * @since 2.1
+     * @param array  the array to search
+     * @param valueToFind  the value to find
+     * @param tolerance  the array contains the tolerance of the search
+     * @return true if value falling within tolerance is in array
      */
-    public static int getLength(final Object array) {
-        if (array == null) {
-            return 0;
-        }
-        return Array.getLength(array);
+    public static boolean contains(final double[] array, final double valueToFind, final double tolerance) {
+        return indexOf(array, valueToFind, 0, tolerance) != INDEX_NOT_FOUND;
     }
 
     /**
-     * <p>Checks whether two arrays are the same type taking into account
-     * multi-dimensional arrays.
+     * <p>Checks if the value is in the given array.
      *
-     * @param array1 the first array, must not be {@code null}
-     * @param array2 the second array, must not be {@code null}
-     * @return {@code true} if type of arrays matches
-     * @throws IllegalArgumentException if either array is {@code null}
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     *
+     * @param array  the array to search through
+     * @param valueToFind  the value to find
+     * @return {@code true} if the array contains the object
      */
-    public static boolean isSameType(final Object array1, final Object array2) {
-        if (array1 == null || array2 == null) {
-            throw new IllegalArgumentException("The Array must not be null");
-        }
-        return array1.getClass().getName().equals(array2.getClass().getName());
+    public static boolean contains(final float[] array, final float valueToFind) {
+        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
     }
 
-    // Reverse
-    //-----------------------------------------------------------------------
     /**
-     * <p>Reverses the order of the given array.
-     *
-     * <p>There is no special handling for multi-dimensional arrays.
+     * <p>Checks if the value is in the given array.
      *
-     * <p>This method does nothing for a {@code null} input array.
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
      *
-     * @param array  the array to reverse, may be {@code null}
+     * @param array  the array to search through
+     * @param valueToFind  the value to find
+     * @return {@code true} if the array contains the object
      */
-    public static void reverse(final Object[] array) {
-        if (array == null) {
-            return;
-        }
-        reverse(array, 0, array.length);
+    public static boolean contains(final int[] array, final int valueToFind) {
+        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
     }
 
     /**
-     * <p>Reverses the order of the given array.
+     * <p>Checks if the value is in the given array.
      *
-     * <p>This method does nothing for a {@code null} input array.
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
      *
-     * @param array  the array to reverse, may be {@code null}
+     * @param array  the array to search through
+     * @param valueToFind  the value to find
+     * @return {@code true} if the array contains the object
      */
-    public static void reverse(final long[] array) {
-        if (array == null) {
-            return;
-        }
-        reverse(array, 0, array.length);
+    public static boolean contains(final long[] array, final long valueToFind) {
+        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
     }
 
     /**
-     * <p>Reverses the order of the given array.
+     * <p>Checks if the object is in the given array.
      *
-     * <p>This method does nothing for a {@code null} input array.
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
      *
-     * @param array  the array to reverse, may be {@code null}
+     * @param array  the array to search through
+     * @param objectToFind  the object to find
+     * @return {@code true} if the array contains the object
      */
-    public static void reverse(final int[] array) {
-        if (array == null) {
-            return;
-        }
-        reverse(array, 0, array.length);
+    public static boolean contains(final Object[] array, final Object objectToFind) {
+        return indexOf(array, objectToFind) != INDEX_NOT_FOUND;
     }
 
     /**
-     * <p>Reverses the order of the given array.
+     * <p>Checks if the value is in the given array.
      *
-     * <p>This method does nothing for a {@code null} input array.
+     * <p>The method returns {@code false} if a {@code null} array is passed in.
      *
-     * @param array  the array to reverse, may be {@code null}
+     * @param array  the array to search through
+     * @param valueToFind  the value to find
+     * @return {@code true} if the array contains the object
      */
-    public static void reverse(final short[] array) {
-        if (array == null) {
-            return;
-        }
-        reverse(array, 0, array.length);
+    public static boolean contains(final short[] array, final short valueToFind) {
+        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
     }
 
     /**
-     * <p>Reverses the order of the given array.
-     *
-     * <p>This method does nothing for a {@code null} input array.
+     * Returns a copy of the given array of size 1 greater than the argument.
+     * The last value of the array is left to the default value.
      *
-     * @param array  the array to reverse, may be {@code null}
+     * @param array The array to copy, must not be {@code null}.
+     * @param newArrayComponentType If {@code array} is {@code null}, create a
+     * size 1 array of this type.
+     * @return A new copy of the array of size 1 greater than the input.
      */
-    public static void reverse(final char[] array) {
-        if (array == null) {
-            return;
+    private static Object copyArrayGrow1(final Object array, final Class<?> newArrayComponentType) {
+        if (array != null) {
+            final int arrayLength = Array.getLength(array);
+            final Object newArray = Array.newInstance(array.getClass().getComponentType(), arrayLength + 1);
+            System.arraycopy(array, 0, newArray, 0, arrayLength);
+            return newArray;
         }
-        reverse(array, 0, array.length);
+        return Array.newInstance(newArrayComponentType, 1);
     }
 
+    //-----------------------------------------------------------------------
     /**
-     * <p>Reverses the order of the given array.
+     * <p>Returns the length of the specified array.
+     * This method can deal with {@code Object} arrays and with primitive arrays.
      *
-     * <p>This method does nothing for a {@code null} input array.
+     * <p>If the input array is {@code null}, {@code 0} is returned.
      *
-     * @param array  the array to reverse, may be {@code null}
+     * <pre>
+     * ArrayUtils.getLength(null)            = 0
+     * ArrayUtils.getLength([])              = 0
+     * ArrayUtils.getLength([null])          = 1
+     * ArrayUtils.getLength([true, false])   = 2
+     * ArrayUtils.getLength([1, 2, 3])       = 3
+     * ArrayUtils.getLength(["a", "b", "c"]) = 3
+     * </pre>
+     *
+     * @param array  the array to retrieve the length from, may be null
+     * @return The length of the array, or {@code 0} if the array is {@code null}
+     * @throws IllegalArgumentException if the object argument is not an array.
+     * @since 2.1
      */
-    public static void reverse(final byte[] array) {
+    public static int getLength(final Object array) {
         if (array == null) {
-            return;
+            return 0;
         }
-        reverse(array, 0, array.length);
+        return Array.getLength(array);
     }
 
     /**
-     * <p>Reverses the order of the given array.
+     * <p>Get a hash code for an array handling multi-dimensional arrays correctly.
      *
-     * <p>This method does nothing for a {@code null} input array.
+     * <p>Multi-dimensional primitive arrays are also handled correctly by this method.
      *
-     * @param array  the array to reverse, may be {@code null}
+     * @param array  the array to get a hash code for, {@code null} returns zero
+     * @return a hash code for the array
      */
-    public static void reverse(final double[] array) {
-        if (array == null) {
-            return;
-        }
-        reverse(array, 0, array.length);
+    public static int hashCode(final Object array) {
+        return new HashCodeBuilder().append(array).toHashCode();
     }
 
     /**
-     * <p>Reverses the order of the given array.
+     * Finds the indices of the given value in the array.
      *
-     * <p>This method does nothing for a {@code null} input array.
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array  the array to reverse, may be {@code null}
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return a BitSet of all the the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final float[] array) {
-        if (array == null) {
-            return;
-        }
-        reverse(array, 0, array.length);
+    public static BitSet indexesOf(final boolean[] array, final boolean valueToFind) {
+        return indexesOf(array, valueToFind, 0);
     }
 
     /**
-     * <p>Reverses the order of the given array.
+     * Finds the indices of the given value in the array starting at the given index.
      *
-     * <p>This method does nothing for a {@code null} input array.
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array  the array to reverse, may be {@code null}
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet ({@code -1}).</p>
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null}
+     *  array input
+     * @since 3.10
      */
-    public static void reverse(final boolean[] array) {
+    public static BitSet indexesOf(final boolean[] array, final boolean valueToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
         if (array == null) {
-            return;
+            return bitSet;
         }
-        reverse(array, 0, array.length);
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
+        }
+
+        return bitSet;
     }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value in the array.
      *
-     * <p>
-     * This method does nothing for a {@code null} input array.
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final boolean[] array, final int startIndexInclusive, final int endIndexExclusive) {
-        if (array == null) {
-            return;
-        }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        boolean tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
-        }
+    public static BitSet indexesOf(final byte[] array, final byte valueToFind) {
+        return indexesOf(array, valueToFind, 0);
     }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value in the array starting at the given index.
      *
-     * <p>
-     * This method does nothing for a {@code null} input array.
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet.</p>
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final byte[] array, final int startIndexInclusive, final int endIndexExclusive) {
+    public static BitSet indexesOf(final byte[] array, final byte valueToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
         if (array == null) {
-            return;
-        }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        byte tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
+            return bitSet;
         }
-    }
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
+        }
+
+        return bitSet;
+    }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value in the array.
      *
-     * <p>
-     * This method does nothing for a {@code null} input array.
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final char[] array, final int startIndexInclusive, final int endIndexExclusive) {
-        if (array == null) {
-            return;
-        }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        char tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
-        }
+    public static BitSet indexesOf(final char[] array, final char valueToFind) {
+        return indexesOf(array, valueToFind, 0);
     }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value in the array starting at the given index.
      *
-     * <p>
-     * This method does nothing for a {@code null} input array.
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet.</p>
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final double[] array, final int startIndexInclusive, final int endIndexExclusive) {
+    public static BitSet indexesOf(final char[] array, final char valueToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
         if (array == null) {
-            return;
+            return bitSet;
         }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        double tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
         }
+
+        return bitSet;
     }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value in the array.
      *
-     * <p>
-     * This method does nothing for a {@code null} input array.
+     * <p>This method returns empty BitSet for a {@code null} input array.</p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final float[] array, final int startIndexInclusive, final int endIndexExclusive) {
-        if (array == null) {
-            return;
-        }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        float tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
-        }
+    public static BitSet indexesOf(final double[] array, final double valueToFind) {
+        return indexesOf(array, valueToFind, 0);
     }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value within a given tolerance in the array.
      *
      * <p>
-     * This method does nothing for a {@code null} input array.
+     * This method will return all the indices of the value which fall between the region
+     * defined by valueToFind - tolerance and valueToFind + tolerance, each time between the nearest integers.
+     * </p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param tolerance tolerance of the search
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final int[] array, final int startIndexInclusive, final int endIndexExclusive) {
-        if (array == null) {
-            return;
-        }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        int tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
-        }
+    public static BitSet indexesOf(final double[] array, final double valueToFind, final double tolerance) {
+        return indexesOf(array, valueToFind, 0, tolerance);
     }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value in the array starting at the given index.
      *
-     * <p>
-     * This method does nothing for a {@code null} input array.
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet.</p>
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final long[] array, final int startIndexInclusive, final int endIndexExclusive) {
+    public static BitSet indexesOf(final double[] array, final double valueToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
         if (array == null) {
-            return;
+            return bitSet;
         }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        long tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
         }
+
+        return bitSet;
     }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value in the array starting at the given index.
      *
      * <p>
-     * This method does nothing for a {@code null} input array.
+     * This method will return the indices of the values which fall between the region
+     * defined by valueToFind - tolerance and valueToFind + tolerance, between the nearest integers.
+     * </p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Under value (&lt;0) is promoted to 0, over value (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Under value (&lt; start index) results in no
-     *            change. Over value (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     *
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet.</p>
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @param tolerance tolerance of the search
+     * @return a BitSet of the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final Object[] array, final int startIndexInclusive, final int endIndexExclusive) {
+    public static BitSet indexesOf(final double[] array, final double valueToFind, int startIndex, final double tolerance) {
+        BitSet bitSet = new BitSet();
+
         if (array == null) {
-            return;
+            return bitSet;
         }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        Object tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex, tolerance);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
         }
+
+        return bitSet;
     }
 
     /**
-     * <p>
-     * Reverses the order of the given array in the given range.
+     * Finds the indices of the given value in the array.
      *
-     * <p>
-     * This method does nothing for a {@code null} input array.
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array
-     *            the array to reverse, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are reversed in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @since 3.2
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void reverse(final short[] array, final int startIndexInclusive, final int endIndexExclusive) {
-        if (array == null) {
-            return;
-        }
-        int i = startIndexInclusive < 0 ? 0 : startIndexInclusive;
-        int j = Math.min(array.length, endIndexExclusive) - 1;
-        short tmp;
-        while (j > i) {
-            tmp = array[j];
-            array[j] = array[i];
-            array[i] = tmp;
-            j--;
-            i++;
-        }
+    public static BitSet indexesOf(final float[] array, final float valueToFind) {
+        return indexesOf(array, valueToFind, 0);
     }
 
-    // Swap
-    //-----------------------------------------------------------------------
     /**
-     * Swaps two elements in the given array.
+     * Finds the indices of the given value in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap(["1", "2", "3"], 0, 2) -&gt; ["3", "2", "1"]</li>
-     *     <li>ArrayUtils.swap(["1", "2", "3"], 0, 0) -&gt; ["1", "2", "3"]</li>
-     *     <li>ArrayUtils.swap(["1", "2", "3"], 1, 0) -&gt; ["2", "1", "3"]</li>
-     *     <li>ArrayUtils.swap(["1", "2", "3"], 0, 5) -&gt; ["1", "2", "3"]</li>
-     *     <li>ArrayUtils.swap(["1", "2", "3"], -1, 1) -&gt; ["2", "1", "3"]</li>
-     * </ul>
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return empty BitSet.</p>
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final Object[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
+    public static BitSet indexesOf(final float[] array, final float valueToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
+        if (array == null) {
+            return bitSet;
         }
-        swap(array, offset1, offset2, 1);
-    }
 
-    /**
-     * Swaps two elements in the given long array.
-     *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
-     *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([true, false, true], 0, 2) -&gt; [true, false, true]</li>
-     *     <li>ArrayUtils.swap([true, false, true], 0, 0) -&gt; [true, false, true]</li>
-     *     <li>ArrayUtils.swap([true, false, true], 1, 0) -&gt; [false, true, true]</li>
-     *     <li>ArrayUtils.swap([true, false, true], 0, 5) -&gt; [true, false, true]</li>
-     *     <li>ArrayUtils.swap([true, false, true], -1, 1) -&gt; [false, true, true]</li>
-     * </ul>
-     *
-     *
-     * @param array  the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
-     */
-    public static void swap(final long[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
         }
-        swap(array, offset1, offset2, 1);
+
+        return bitSet;
     }
 
     /**
-     * Swaps two elements in the given int array.
-     *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
+     * Finds the indices of the given value in the array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 2) -&gt; [3, 2, 1]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 0) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 1, 0) -&gt; [2, 1, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 5) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], -1, 1) -&gt; [2, 1, 3]</li>
-     * </ul>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array  the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final int[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
-        }
-        swap(array, offset1, offset2, 1);
+    public static BitSet indexesOf(final int[] array, final int valueToFind) {
+        return indexesOf(array, valueToFind, 0);
     }
 
     /**
-     * Swaps two elements in the given short array.
+     * Finds the indices of the given value in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 2) -&gt; [3, 2, 1]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 0) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 1, 0) -&gt; [2, 1, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 5) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], -1, 1) -&gt; [2, 1, 3]</li>
-     * </ul>
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet.</p>
      *
-     * @param array  the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final short[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
+    public static BitSet indexesOf(final int[] array, final int valueToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
+        if (array == null) {
+            return bitSet;
         }
-        swap(array, offset1, offset2, 1);
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
+        }
+
+        return bitSet;
     }
 
     /**
-     * Swaps two elements in the given char array.
-     *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
+     * Finds the indices of the given value in the array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 2) -&gt; [3, 2, 1]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 0) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 1, 0) -&gt; [2, 1, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 5) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], -1, 1) -&gt; [2, 1, 3]</li>
-     * </ul>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array  the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final char[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
-        }
-        swap(array, offset1, offset2, 1);
+    public static BitSet indexesOf(final long[] array, final long valueToFind) {
+        return indexesOf(array, valueToFind, 0);
     }
 
     /**
-     * Swaps two elements in the given byte array.
+     * Finds the indices of the given value in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 2) -&gt; [3, 2, 1]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 0) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 1, 0) -&gt; [2, 1, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 5) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], -1, 1) -&gt; [2, 1, 3]</li>
-     * </ul>
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet.</p>
      *
-     * @param array  the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final byte[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
+    public static BitSet indexesOf(final long[] array, final long valueToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
+        if (array == null) {
+            return bitSet;
         }
-        swap(array, offset1, offset2, 1);
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
+        }
+
+        return bitSet;
     }
 
     /**
-     * Swaps two elements in the given double array.
-     *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
+     * Finds the indices of the given object in the array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 2) -&gt; [3, 2, 1]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 0) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 1, 0) -&gt; [2, 1, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 5) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], -1, 1) -&gt; [2, 1, 3]</li>
-     * </ul>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array  the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param objectToFind  the object to find, may be {@code null}
+     * @return a BitSet of all the indices of the object within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final double[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
-        }
-        swap(array, offset1, offset2, 1);
+    public static BitSet indexesOf(final Object[] array, final Object objectToFind) {
+        return indexesOf(array, objectToFind, 0);
     }
 
     /**
-     * Swaps two elements in the given float array.
+     * Finds the indices of the given object in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 2) -&gt; [3, 2, 1]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 0) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 1, 0) -&gt; [2, 1, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 5) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], -1, 1) -&gt; [2, 1, 3]</li>
-     * </ul>
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet.</p>
      *
-     * @param array  the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param objectToFind  the object to find, may be {@code null}
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of all the indices of the object within the array starting at the index,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final float[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
+    public static BitSet indexesOf(final Object[] array, final Object objectToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
+        if (array == null) {
+            return bitSet;
         }
-        swap(array, offset1, offset2, 1);
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, objectToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
+        }
+
+        return bitSet;
     }
 
     /**
-     * Swaps two elements in the given boolean array.
-     *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for a {@code null} or empty input array or for overflow indices.
-     * Negative indices are promoted to 0(zero).</p>
+     * Finds the indices of the given value in the array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 2) -&gt; [3, 2, 1]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 0) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 1, 0) -&gt; [2, 1, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], 0, 5) -&gt; [1, 2, 3]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3], -1, 1) -&gt; [2, 1, 3]</li>
-     * </ul>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * @param array  the array to swap, may be {@code null}
-     * @param offset1 the index of the first element to swap
-     * @param offset2 the index of the second element to swap
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final boolean[] array, final int offset1, final int offset2) {
-        if (isEmpty(array)) {
-            return;
-        }
-        swap(array, offset1, offset2, 1);
+    public static BitSet indexesOf(final short[] array, final short valueToFind) {
+        return indexesOf(array, valueToFind, 0);
     }
 
     /**
-     * Swaps a series of elements in the given boolean array.
+     * Finds the indices of the given value in the array starting at the given index.
      *
-     * <p>This method does nothing for a {@code null} or empty input array or
-     * for overflow indices. Negative indices are promoted to 0(zero). If any
-     * of the sub-arrays to swap falls outside of the given array, then the
-     * swap is stopped at the end of the array and as many as possible elements
-     * are swapped.</p>
+     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([true, false, true, false], 0, 2, 1) -&gt; [true, false, true, false]</li>
-     *     <li>ArrayUtils.swap([true, false, true, false], 0, 0, 1) -&gt; [true, false, true, false]</li>
-     *     <li>ArrayUtils.swap([true, false, true, false], 0, 2, 2) -&gt; [true, false, true, false]</li>
-     *     <li>ArrayUtils.swap([true, false, true, false], -3, 2, 2) -&gt; [true, false, true, false]</li>
-     *     <li>ArrayUtils.swap([true, false, true, false], 0, 3, 3) -&gt; [false, false, true, true]</li>
-     * </ul>
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return an empty BitSet.</p>
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element in the series to swap
-     * @param offset2 the index of the second element in the series to swap
-     * @param len the number of elements to swap starting with the given indices
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return a BitSet of all the indices of the value within the array,
+     *  an empty BitSet if not found or {@code null} array input
+     * @since 3.10
      */
-    public static void swap(final boolean[] array, int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
-        }
-        if (offset2 < 0) {
-            offset2 = 0;
+    public static BitSet indexesOf(final short[] array, final short valueToFind, int startIndex) {
+        BitSet bitSet = new BitSet();
+
+        if (array == null) {
+            return bitSet;
         }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final boolean aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
+
+        while (startIndex < array.length) {
+            startIndex = indexOf(array, valueToFind, startIndex);
+
+            if (startIndex == INDEX_NOT_FOUND) {
+                break;
+            }
+
+            bitSet.set(startIndex);
+            ++startIndex;
         }
+
+        return bitSet;
     }
 
+    // boolean IndexOf
+    //-----------------------------------------------------------------------
     /**
-     * Swaps a series of elements in the given byte array.
-     *
-     * <p>This method does nothing for a {@code null} or empty input array or
-     * for overflow indices. Negative indices are promoted to 0(zero). If any
-     * of the sub-arrays to swap falls outside of the given array, then the
-     * swap is stopped at the end of the array and as many as possible elements
-     * are swapped.</p>
+     * <p>Finds the index of the given value in the array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -&gt; [3, 2, 1, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -&gt; [1, 2, 3, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -&gt; [4, 2, 3, 1]</li>
-     * </ul>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element in the series to swap
-     * @param offset2 the index of the second element in the series to swap
-     * @param len the number of elements to swap starting with the given indices
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void swap(final byte[] array, int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
-        }
-        if (offset2 < 0) {
-            offset2 = 0;
-        }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final byte aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
-        }
+    public static int indexOf(final boolean[] array, final boolean valueToFind) {
+        return indexOf(array, valueToFind, 0);
     }
 
     /**
-     * Swaps a series of elements in the given char array.
+     * <p>Finds the index of the given value in the array starting at the given index.
      *
-     * <p>This method does nothing for a {@code null} or empty input array or
-     * for overflow indices. Negative indices are promoted to 0(zero). If any
-     * of the sub-arrays to swap falls outside of the given array, then the
-     * swap is stopped at the end of the array and as many as possible elements
-     * are swapped.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -&gt; [3, 2, 1, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -&gt; [1, 2, 3, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -&gt; [4, 2, 3, 1]</li>
-     * </ul>
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element in the series to swap
-     * @param offset2 the index of the second element in the series to swap
-     * @param len the number of elements to swap starting with the given indices
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null}
+     *  array input
      */
-    public static void swap(final char[] array, int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
+    public static int indexOf(final boolean[] array, final boolean valueToFind, int startIndex) {
+        if (isEmpty(array)) {
+            return INDEX_NOT_FOUND;
         }
-        if (offset2 < 0) {
-            offset2 = 0;
+        if (startIndex < 0) {
+            startIndex = 0;
         }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final char aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
+        for (int i = startIndex; i < array.length; i++) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
         }
+        return INDEX_NOT_FOUND;
     }
 
+    // byte IndexOf
+    //-----------------------------------------------------------------------
     /**
-     * Swaps a series of elements in the given double array.
-     *
-     * <p>This method does nothing for a {@code null} or empty input array or
-     * for overflow indices. Negative indices are promoted to 0(zero). If any
-     * of the sub-arrays to swap falls outside of the given array, then the
-     * swap is stopped at the end of the array and as many as possible elements
-     * are swapped.</p>
+     * <p>Finds the index of the given value in the array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -&gt; [3, 2, 1, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -&gt; [1, 2, 3, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -&gt; [4, 2, 3, 1]</li>
-     * </ul>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element in the series to swap
-     * @param offset2 the index of the second element in the series to swap
-     * @param len the number of elements to swap starting with the given indices
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void swap(final double[] array,  int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
-        }
-        if (offset2 < 0) {
-            offset2 = 0;
-        }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final double aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
-        }
+    public static int indexOf(final byte[] array, final byte valueToFind) {
+        return indexOf(array, valueToFind, 0);
     }
 
     /**
-     * Swaps a series of elements in the given float array.
+     * <p>Finds the index of the given value in the array starting at the given index.
      *
-     * <p>This method does nothing for a {@code null} or empty input array or
-     * for overflow indices. Negative indices are promoted to 0(zero). If any
-     * of the sub-arrays to swap falls outside of the given array, then the
-     * swap is stopped at the end of the array and as many as possible elements
-     * are swapped.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -&gt; [3, 2, 1, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -&gt; [1, 2, 3, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -&gt; [4, 2, 3, 1]</li>
-     * </ul>
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element in the series to swap
-     * @param offset2 the index of the second element in the series to swap
-     * @param len the number of elements to swap starting with the given indices
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void swap(final float[] array, int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
+    public static int indexOf(final byte[] array, final byte valueToFind, int startIndex) {
+        if (array == null) {
+            return INDEX_NOT_FOUND;
         }
-        if (offset2 < 0) {
-            offset2 = 0;
+        if (startIndex < 0) {
+            startIndex = 0;
         }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final float aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
+        for (int i = startIndex; i < array.length; i++) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
         }
-
+        return INDEX_NOT_FOUND;
     }
 
+    // char IndexOf
+    //-----------------------------------------------------------------------
     /**
-     * Swaps a series of elements in the given int array.
-     *
-     * <p>This method does nothing for a {@code null} or empty input array or
-     * for overflow indices. Negative indices are promoted to 0(zero). If any
-     * of the sub-arrays to swap falls outside of the given array, then the
-     * swap is stopped at the end of the array and as many as possible elements
-     * are swapped.</p>
+     * <p>Finds the index of the given value in the array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -&gt; [3, 2, 1, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -&gt; [1, 2, 3, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -&gt; [4, 2, 3, 1]</li>
-     * </ul>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element in the series to swap
-     * @param offset2 the index of the second element in the series to swap
-     * @param len the number of elements to swap starting with the given indices
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @since 2.1
      */
-    public static void swap(final int[] array,  int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
-        }
-        if (offset2 < 0) {
-            offset2 = 0;
-        }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final int aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
-        }
+    public static int indexOf(final char[] array, final char valueToFind) {
+        return indexOf(array, valueToFind, 0);
     }
 
     /**
-     * Swaps a series of elements in the given long array.
+     * <p>Finds the index of the given value in the array starting at the given index.
      *
-     * <p>This method does nothing for a {@code null} or empty input array or
-     * for overflow indices. Negative indices are promoted to 0(zero). If any
-     * of the sub-arrays to swap falls outside of the given array, then the
-     * swap is stopped at the end of the array and as many as possible elements
-     * are swapped.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -&gt; [3, 2, 1, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -&gt; [1, 2, 3, 4]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -&gt; [3, 4, 1, 2]</li>
-     *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -&gt; [4, 2, 3, 1]</li>
-     * </ul>
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element in the series to swap
-     * @param offset2 the index of the second element in the series to swap
-     * @param len the number of elements to swap starting with the given indices
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @since 2.1
      */
-    public static void swap(final long[] array,  int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
+    public static int indexOf(final char[] array, final char valueToFind, int startIndex) {
+        if (array == null) {
+            return INDEX_NOT_FOUND;
         }
-        if (offset2 < 0) {
-            offset2 = 0;
+        if (startIndex < 0) {
+            startIndex = 0;
         }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final long aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
+        for (int i = startIndex; i < array.length; i++) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
         }
+        return INDEX_NOT_FOUND;
     }
 
+    // double IndexOf
+    //-----------------------------------------------------------------------
     /**
-     * Swaps a series of elements in the given array.
+     * <p>Finds the index of the given value in the array.
      *
-     * <p>This method does nothing for a {@code null} or empty input array or
-     * for overflow indices. Negative indices are promoted to 0(zero). If any
-     * of the sub-arrays to swap falls outside of the given array, then the
-     * swap is stopped at the end of the array and as many as possible elements
-     * are swapped.</p>
-     *
-     * Examples:
-     * <ul>
-     *     <li>ArrayUtils.swap(["1", "2", "3", "4"], 0, 2, 1) -&gt; ["3", "2", "1", "4"]</li>
-     *     <li>ArrayUtils.swap(["1", "2", "3", "4"], 0, 0, 1) -&gt; ["1", "2", "3", "4"]</li>
-     *     <li>ArrayUtils.swap(["1", "2", "3", "4"], 2, 0, 2) -&gt; ["3", "4", "1", "2"]</li>
-     *     <li>ArrayUtils.swap(["1", "2", "3", "4"], -3, 2, 2) -&gt; ["3", "4", "1", "2"]</li>
-     *     <li>ArrayUtils.swap(["1", "2", "3", "4"], 0, 3, 3) -&gt; ["4", "2", "3", "1"]</li>
-     * </ul>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array the array to swap, may be {@code null}
-     * @param offset1 the index of the first element in the series to swap
-     * @param offset2 the index of the second element in the series to swap
-     * @param len the number of elements to swap starting with the given indices
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void swap(final Object[] array,  int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
-        }
-        if (offset2 < 0) {
-            offset2 = 0;
-        }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final Object aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
-        }
-    }
-
-   /**
-    * Swaps a series of elements in the given short array.
-    *
-    * <p>This method does nothing for a {@code null} or empty input array or
-    * for overflow indices. Negative indices are promoted to 0(zero). If any
-    * of the sub-arrays to swap falls outside of the given array, then the
-    * swap is stopped at the end of the array and as many as possible elements
-    * are swapped.</p>
-    *
-    * Examples:
-    * <ul>
-    *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -&gt; [3, 2, 1, 4]</li>
-    *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -&gt; [1, 2, 3, 4]</li>
-    *     <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -&gt; [3, 4, 1, 2]</li>
-    *     <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -&gt; [3, 4, 1, 2]</li>
-    *     <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -&gt; [4, 2, 3, 1]</li>
-    * </ul>
-    *
-    * @param array the array to swap, may be {@code null}
-    * @param offset1 the index of the first element in the series to swap
-    * @param offset2 the index of the second element in the series to swap
-    * @param len the number of elements to swap starting with the given indices
-    * @since 3.5
-    */
-    public static void swap(final short[] array,  int offset1, int offset2, int len) {
-        if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) {
-            return;
-        }
-        if (offset1 < 0) {
-            offset1 = 0;
-        }
-        if (offset2 < 0) {
-            offset2 = 0;
-        }
-        if (offset1 == offset2) {
-            return;
-        }
-        len = Math.min(Math.min(len, array.length - offset1), array.length - offset2);
-        for (int i = 0; i < len; i++, offset1++, offset2++) {
-            final short aux = array[offset1];
-            array[offset1] = array[offset2];
-            array[offset2] = aux;
-        }
+    public static int indexOf(final double[] array, final double valueToFind) {
+        return indexOf(array, valueToFind, 0);
     }
 
-    // Shift
-    //-----------------------------------------------------------------------
     /**
-     * Shifts the order of the given array.
+     * <p>Finds the index of the given value within a given tolerance in the array.
+     * This method will return the index of the first value which falls between the region
+     * defined by valueToFind - tolerance and valueToFind + tolerance.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param tolerance tolerance of the search
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final Object[] array, final int offset) {
-        if (array == null) {
-            return;
-        }
-        shift(array, 0, array.length, offset);
+    public static int indexOf(final double[] array, final double valueToFind, final double tolerance) {
+        return indexOf(array, valueToFind, 0, tolerance);
     }
 
     /**
-     * Shifts the order of the given long array.
+     * <p>Finds the index of the given value in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final long[] array, final int offset) {
-        if (array == null) {
-            return;
+    public static int indexOf(final double[] array, final double valueToFind, int startIndex) {
+        if (isEmpty(array)) {
+            return INDEX_NOT_FOUND;
         }
-        shift(array, 0, array.length, offset);
+        if (startIndex < 0) {
+            startIndex = 0;
+        }
+        for (int i = startIndex; i < array.length; i++) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
+        }
+        return INDEX_NOT_FOUND;
     }
 
     /**
-     * Shifts the order of the given int array.
+     * <p>Finds the index of the given value in the array starting at the given index.
+     * This method will return the index of the first value which falls between the region
+     * defined by valueToFind - tolerance and valueToFind + tolerance.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @param tolerance tolerance of the search
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final int[] array, final int offset) {
-        if (array == null) {
-            return;
+    public static int indexOf(final double[] array, final double valueToFind, int startIndex, final double tolerance) {
+        if (isEmpty(array)) {
+            return INDEX_NOT_FOUND;
         }
-        shift(array, 0, array.length, offset);
+        if (startIndex < 0) {
+            startIndex = 0;
+        }
+        final double min = valueToFind - tolerance;
+        final double max = valueToFind + tolerance;
+        for (int i = startIndex; i < array.length; i++) {
+            if (array[i] >= min && array[i] <= max) {
+                return i;
+            }
+        }
+        return INDEX_NOT_FOUND;
     }
 
+    // float IndexOf
+    //-----------------------------------------------------------------------
     /**
-     * Shifts the order of the given short array.
+     * <p>Finds the index of the given value in the array.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final short[] array, final int offset) {
-        if (array == null) {
-            return;
-        }
-        shift(array, 0, array.length, offset);
+    public static int indexOf(final float[] array, final float valueToFind) {
+        return indexOf(array, valueToFind, 0);
     }
 
     /**
-     * Shifts the order of the given char array.
+     * <p>Finds the index of the given value in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final char[] array, final int offset) {
-        if (array == null) {
-            return;
+    public static int indexOf(final float[] array, final float valueToFind, int startIndex) {
+        if (isEmpty(array)) {
+            return INDEX_NOT_FOUND;
         }
-        shift(array, 0, array.length, offset);
+        if (startIndex < 0) {
+            startIndex = 0;
+        }
+        for (int i = startIndex; i < array.length; i++) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
+        }
+        return INDEX_NOT_FOUND;
     }
 
+   // int IndexOf
+//-----------------------------------------------------------------------
+/**
+ * <p>Finds the index of the given value in the array.
+ *
+ * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+ *
+ * @param array  the array to search through for the object, may be {@code null}
+ * @param valueToFind  the value to find
+ * @return the index of the value within the array,
+ *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+ */
+public static int indexOf(final int[] array, final int valueToFind) {
+    return indexOf(array, valueToFind, 0);
+}
+
     /**
-     * Shifts the order of the given byte array.
+     * <p>Finds the index of the given value in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final byte[] array, final int offset) {
+    public static int indexOf(final int[] array, final int valueToFind, int startIndex) {
         if (array == null) {
-            return;
+            return INDEX_NOT_FOUND;
         }
-        shift(array, 0, array.length, offset);
+        if (startIndex < 0) {
+            startIndex = 0;
+        }
+        for (int i = startIndex; i < array.length; i++) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
+        }
+        return INDEX_NOT_FOUND;
     }
 
+    // long IndexOf
+    //-----------------------------------------------------------------------
     /**
-     * Shifts the order of the given double array.
+     * <p>Finds the index of the given value in the array.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final double[] array, final int offset) {
-        if (array == null) {
-            return;
-        }
-        shift(array, 0, array.length, offset);
+    public static int indexOf(final long[] array, final long valueToFind) {
+        return indexOf(array, valueToFind, 0);
     }
 
     /**
-     * Shifts the order of the given float array.
+     * <p>Finds the index of the given value in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final float[] array, final int offset) {
+    public static int indexOf(final long[] array, final long valueToFind, int startIndex) {
         if (array == null) {
-            return;
+            return INDEX_NOT_FOUND;
         }
-        shift(array, 0, array.length, offset);
+        if (startIndex < 0) {
+            startIndex = 0;
+        }
+        for (int i = startIndex; i < array.length; i++) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
+        }
+        return INDEX_NOT_FOUND;
     }
 
+    // Object IndexOf
+    //-----------------------------------------------------------------------
     /**
-     * Shifts the order of the given boolean array.
+     * <p>Finds the index of the given object in the array.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to shift, may be {@code null}
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param objectToFind  the object to find, may be {@code null}
+     * @return the index of the object within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final boolean[] array, final int offset) {
-        if (array == null) {
-            return;
-        }
-        shift(array, 0, array.length, offset);
+    public static int indexOf(final Object[] array, final Object objectToFind) {
+        return indexOf(array, objectToFind, 0);
     }
 
     /**
-     * Shifts the order of a series of elements in the given boolean array.
+     * <p>Finds the index of the given object in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param objectToFind  the object to find, may be {@code null}
+     * @param startIndex  the index to start searching at
+     * @return the index of the object within the array starting at the index,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final boolean[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
+    public static int indexOf(final Object[] array, final Object objectToFind, int startIndex) {
         if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
-        }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
+            return INDEX_NOT_FOUND;
         }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
+        if (startIndex < 0) {
+            startIndex = 0;
         }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
-
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
+        if (objectToFind == null) {
+            for (int i = startIndex; i < array.length; i++) {
+                if (array[i] == null) {
+                    return i;
+                }
+            }
+        } else {
+            for (int i = startIndex; i < array.length; i++) {
+                if (objectToFind.equals(array[i])) {
+                    return i;
+                }
             }
         }
+        return INDEX_NOT_FOUND;
     }
 
+    // short IndexOf
+    //-----------------------------------------------------------------------
     /**
-     * Shifts the order of a series of elements in the given byte array.
+     * <p>Finds the index of the given value in the array.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final byte[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
-        if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
-        }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
-        }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
-        }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
-
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
-            }
-        }
+    public static int indexOf(final short[] array, final short valueToFind) {
+        return indexOf(array, valueToFind, 0);
     }
 
     /**
-     * Shifts the order of a series of elements in the given char array.
+     * <p>Finds the index of the given value in the array starting at the given index.
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
+     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     *
+     * @param array  the array to search through for the object, may be {@code null}
+     * @param valueToFind  the value to find
+     * @param startIndex  the index to start searching at
+     * @return the index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static void shift(final char[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
+    public static int indexOf(final short[] array, final short valueToFind, int startIndex) {
         if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
+            return INDEX_NOT_FOUND;
         }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
+        if (startIndex < 0) {
+            startIndex = 0;
         }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
-        }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
-        }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
-        }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
-
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
-            }
+        for (int i = startIndex; i < array.length; i++) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
         }
+        return INDEX_NOT_FOUND;
     }
 
     /**
-     * Shifts the order of a series of elements in the given double array.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
+     *
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static void shift(final double[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
+    public static boolean[] insert(final int index, final boolean[] array, final boolean... values) {
         if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
+            return null;
         }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
         }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
         }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
 
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
-            }
+        final boolean[] result = new boolean[array.length + values.length];
+
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
+        }
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
         }
+        return result;
     }
 
     /**
-     * Shifts the order of a series of elements in the given float array.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
+     *
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static void shift(final float[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
+    public static byte[] insert(final int index, final byte[] array, final byte... values) {
         if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
+            return null;
         }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
         }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
         }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
 
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
-            }
+        final byte[] result = new byte[array.length + values.length];
+
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
+        }
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
         }
+        return result;
     }
 
     /**
-     * Shifts the order of a series of elements in the given int array.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
+     *
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static void shift(final int[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
+    public static char[] insert(final int index, final char[] array, final char... values) {
         if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
+            return null;
         }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
         }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
         }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
+
+        final char[] result = new char[array.length + values.length];
+
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
         }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
         }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
-
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
-            }
-        }
-    }
+        return result;
+    }
 
     /**
-     * Shifts the order of a series of elements in the given long array.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
+     *
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static void shift(final long[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
+    public static double[] insert(final int index, final double[] array, final double... values) {
         if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
+            return null;
         }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
         }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
         }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
 
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
-            }
+        final double[] result = new double[array.length + values.length];
+
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
+        }
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
         }
+        return result;
     }
 
     /**
-     * Shifts the order of a series of elements in the given array.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
+     *
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static void shift(final Object[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
+    public static float[] insert(final int index, final float[] array, final float... values) {
         if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
+            return null;
         }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
         }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
         }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
 
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
-            }
+        final float[] result = new float[array.length + values.length];
+
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
+        }
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
         }
+        return result;
     }
 
     /**
-     * Shifts the order of a series of elements in the given short array.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>There is no special handling for multi-dimensional arrays. This method
-     * does nothing for {@code null} or empty input arrays.</p>
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * @param array
-     *            the array to shift, may be {@code null}
-     * @param startIndexInclusive
-     *            the starting index. Undervalue (&lt;0) is promoted to 0, overvalue (&gt;array.length) results in no
-     *            change.
-     * @param endIndexExclusive
-     *            elements up to endIndex-1 are shifted in the array. Undervalue (&lt; start index) results in no
-     *            change. Overvalue (&gt;array.length) is demoted to array length.
-     * @param offset
-     *          The number of positions to rotate the elements.  If the offset is larger than the number of elements to
-     *          rotate, than the effective offset is modulo the number of elements to rotate.
-     * @since 3.5
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
+     *
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static void shift(final short[] array, int startIndexInclusive, int endIndexExclusive, int offset) {
+    public static int[] insert(final int index, final int[] array, final int... values) {
         if (array == null) {
-            return;
-        }
-        if (startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) {
-            return;
-        }
-        if (startIndexInclusive < 0) {
-            startIndexInclusive = 0;
-        }
-        if (endIndexExclusive >= array.length) {
-            endIndexExclusive = array.length;
+            return null;
         }
-        int n = endIndexExclusive - startIndexInclusive;
-        if (n <= 1) {
-            return;
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
         }
-        offset %= n;
-        if (offset < 0) {
-            offset += n;
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
         }
-        // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity
-        // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/
-        while (n > 1 && offset > 0) {
-            final int n_offset = n - offset;
 
-            if (offset > n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n - n_offset,  n_offset);
-                n = offset;
-                offset -= n_offset;
-            } else if (offset < n_offset) {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset,  offset);
-                startIndexInclusive += offset;
-                n = n_offset;
-            } else {
-                swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset);
-                break;
-            }
+        final int[] result = new int[array.length + values.length];
+
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
+        }
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
         }
+        return result;
     }
 
-    // IndexOf search
-    // ----------------------------------------------------------------------
-
-    // Object IndexOf
-    //-----------------------------------------------------------------------
     /**
-     * <p>Finds the index of the given object in the array.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param objectToFind  the object to find, may be {@code null}
-     * @return the index of the object within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
-     */
-    public static int indexOf(final Object[] array, final Object objectToFind) {
-        return indexOf(array, objectToFind, 0);
-    }
-
-    /**
-     * <p>Finds the index of the given object in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param objectToFind  the object to find, may be {@code null}
-     * @param startIndex  the index to start searching at
-     * @return the index of the object within the array starting at the index,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static int indexOf(final Object[] array, final Object objectToFind, int startIndex) {
+    public static long[] insert(final int index, final long[] array, final long... values) {
         if (array == null) {
-            return INDEX_NOT_FOUND;
+            return null;
         }
-        if (startIndex < 0) {
-            startIndex = 0;
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
         }
-        if (objectToFind == null) {
-            for (int i = startIndex; i < array.length; i++) {
-                if (array[i] == null) {
-                    return i;
-                }
-            }
-        } else {
-            for (int i = startIndex; i < array.length; i++) {
-                if (objectToFind.equals(array[i])) {
-                    return i;
-                }
-            }
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
         }
-        return INDEX_NOT_FOUND;
+
+        final long[] result = new long[array.length + values.length];
+
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
+        }
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
+        }
+        return result;
     }
 
     /**
-     * Finds the indices of the given object in the array.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param objectToFind  the object to find, may be {@code null}
-     * @return a BitSet of all the indices of the object within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
+     *
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static BitSet indexesOf(final Object[] array, final Object objectToFind) {
-        return indexesOf(array, objectToFind, 0);
+    public static short[] insert(final int index, final short[] array, final short... values) {
+        if (array == null) {
+            return null;
+        }
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
+        }
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
+        }
+
+        final short[] result = new short[array.length + values.length];
+
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
+        }
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
+        }
+        return result;
     }
 
     /**
-     * Finds the indices of the given object in the array starting at the given index.
+     * <p>Inserts elements into an array at the given index (starting from zero).</p>
      *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>When an array is returned, it is always a new array.</p>
      *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet.</p>
+     * <pre>
+     * ArrayUtils.insert(index, null, null)      = null
+     * ArrayUtils.insert(index, array, null)     = cloned copy of 'array'
+     * ArrayUtils.insert(index, null, values)    = null
+     * </pre>
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param objectToFind  the object to find, may be {@code null}
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of all the indices of the object within the array starting at the index,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param <T> The type of elements in {@code array} and {@code values}
+     * @param index the position within {@code array} to insert the new values
+     * @param array the array to insert the values into, may be {@code null}
+     * @param values the new values to insert, may be {@code null}
+     * @return The new array.
+     * @throws IndexOutOfBoundsException if {@code array} is provided
+     * and either {@code index < 0} or {@code index > array.length}
+     * @since 3.6
      */
-    public static BitSet indexesOf(final Object[] array, final Object objectToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
+    @SafeVarargs
+    public static <T> T[] insert(final int index, final T[] array, final T... values) {
+        /*
+         * Note on use of @SafeVarargs:
+         *
+         * By returning null when 'array' is null, we avoid returning the vararg
+         * array to the caller. We also avoid relying on the type of the vararg
+         * array, by inspecting the component type of 'array'.
+         */
 
         if (array == null) {
-            return bitSet;
+            return null;
+        }
+        if (ArrayUtils.isEmpty(values)) {
+            return clone(array);
+        }
+        if (index < 0 || index > array.length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length);
         }
 
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, objectToFind, startIndex);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
-            }
+        final Class<?> type = array.getClass().getComponentType();
+        @SuppressWarnings("unchecked") // OK, because array and values are of type T
+        final
+        T[] result = (T[]) Array.newInstance(type, array.length + values.length);
 
-            bitSet.set(startIndex);
-            ++startIndex;
+        System.arraycopy(values, 0, result, index, values.length);
+        if (index > 0) {
+            System.arraycopy(array, 0, result, 0, index);
         }
-
-        return bitSet;
+        if (index < array.length) {
+            System.arraycopy(array, index, result, index + values.length, array.length - index);
+        }
+        return result;
     }
 
+    /**
+     * Returns whether a given array can safely be accessed at the given index.
+     * @param <T> the component type of the array
+     * @param array the array to inspect, may be null
+     * @param index the index of the array to be inspected
+     * @return Whether the given index is safely-accessible in the given array
+     * @since 3.8
+     */
+    public static <T> boolean isArrayIndexValid(T[] array, int index) {
+        if (getLength(array) == 0 || array.length <= index) {
+            return false;
+        }
 
+        return index >= 0;
+    }
 
     /**
-     * <p>Finds the last index of the given object within the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks if an array of primitive booleans is empty or {@code null}.
      *
-     * @param array  the array to traverse backwards looking for the object, may be {@code null}
-     * @param objectToFind  the object to find, may be {@code null}
-     * @return the last index of the object within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static int lastIndexOf(final Object[] array, final Object objectToFind) {
-        return lastIndexOf(array, objectToFind, Integer.MAX_VALUE);
+    public static boolean isEmpty(final boolean[] array) {
+        return getLength(array) == 0;
     }
 
+    // IndexOf search
+    // ----------------------------------------------------------------------
+
     /**
-     * <p>Finds the last index of the given object in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than
-     * the array length will search from the end of the array.
+     * <p>Checks if an array of primitive bytes is empty or {@code null}.
      *
-     * @param array  the array to traverse for looking for the object, may be {@code null}
-     * @param objectToFind  the object to find, may be {@code null}
-     * @param startIndex  the start index to traverse backwards from
-     * @return the last index of the object within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static int lastIndexOf(final Object[] array, final Object objectToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            return INDEX_NOT_FOUND;
-        } else if (startIndex >= array.length) {
-            startIndex = array.length - 1;
-        }
-        if (objectToFind == null) {
-            for (int i = startIndex; i >= 0; i--) {
-                if (array[i] == null) {
-                    return i;
-                }
-            }
-        } else if (array.getClass().getComponentType().isInstance(objectToFind)) {
-            for (int i = startIndex; i >= 0; i--) {
-                if (objectToFind.equals(array[i])) {
-                    return i;
-                }
-            }
-        }
-        return INDEX_NOT_FOUND;
+    public static boolean isEmpty(final byte[] array) {
+        return getLength(array) == 0;
     }
 
     /**
-     * <p>Checks if the object is in the given array.
-     *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     * <p>Checks if an array of primitive chars is empty or {@code null}.
      *
-     * @param array  the array to search through
-     * @param objectToFind  the object to find
-     * @return {@code true} if the array contains the object
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static boolean contains(final Object[] array, final Object objectToFind) {
-        return indexOf(array, objectToFind) != INDEX_NOT_FOUND;
+    public static boolean isEmpty(final char[] array) {
+        return getLength(array) == 0;
     }
 
-    // long IndexOf
-    //-----------------------------------------------------------------------
     /**
-     * <p>Finds the index of the given value in the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks if an array of primitive doubles is empty or {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static int indexOf(final long[] array, final long valueToFind) {
-        return indexOf(array, valueToFind, 0);
+    public static boolean isEmpty(final double[] array) {
+        return getLength(array) == 0;
     }
 
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <p>Checks if an array of primitive floats is empty or {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static int indexOf(final long[] array, final long valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            startIndex = 0;
-        }
-        for (int i = startIndex; i < array.length; i++) {
-            if (valueToFind == array[i]) {
-                return i;
-            }
-        }
-        return INDEX_NOT_FOUND;
+    public static boolean isEmpty(final float[] array) {
+        return getLength(array) == 0;
     }
 
+
+
     /**
-     * Finds the indices of the given value in the array.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>Checks if an array of primitive ints is empty or {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static BitSet indexesOf(final long[] array, final long valueToFind) {
-        return indexesOf(array, valueToFind, 0);
+    public static boolean isEmpty(final int[] array) {
+        return getLength(array) == 0;
     }
 
     /**
-     * Finds the indices of the given value in the array starting at the given index.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet.</p>
+     * <p>Checks if an array of primitive longs is empty or {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static BitSet indexesOf(final long[] array, final long valueToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
-
-        if (array == null) {
-            return bitSet;
-        }
-
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
-            }
-
-            bitSet.set(startIndex);
-            ++startIndex;
-        }
-
-        return bitSet;
+    public static boolean isEmpty(final long[] array) {
+        return getLength(array) == 0;
     }
 
+    // ----------------------------------------------------------------------
     /**
-     * <p>Finds the last index of the given value within the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks if an array of Objects is empty or {@code null}.
      *
-     * @param array  the array to traverse backwards looking for the object, may be {@code null}
-     * @param valueToFind  the object to find
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static int lastIndexOf(final long[] array, final long valueToFind) {
-        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
+    public static boolean isEmpty(final Object[] array) {
+        return getLength(array) == 0;
     }
 
     /**
-     * <p>Finds the last index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
-     * array length will search from the end of the array.
+     * <p>Checks if an array of primitive shorts is empty or {@code null}.
      *
-     * @param array  the array to traverse for looking for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the start index to traverse backwards from
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is empty or {@code null}
+     * @since 2.1
      */
-    public static int lastIndexOf(final long[] array, final long valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            return INDEX_NOT_FOUND;
-        } else if (startIndex >= array.length) {
-            startIndex = array.length - 1;
-        }
-        for (int i = startIndex; i >= 0; i--) {
-            if (valueToFind == array[i]) {
-                return i;
-            }
-        }
-        return INDEX_NOT_FOUND;
+    public static boolean isEmpty(final short[] array) {
+        return getLength(array) == 0;
     }
 
     /**
-     * <p>Checks if the value is in the given array.
+     * <p>Compares two arrays, using equals(), handling multi-dimensional arrays
+     * correctly.
      *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     * <p>Multi-dimensional primitive arrays are also handled correctly by this method.
      *
-     * @param array  the array to search through
-     * @param valueToFind  the value to find
-     * @return {@code true} if the array contains the object
+     * @param array1  the left hand array to compare, may be {@code null}
+     * @param array2  the right hand array to compare, may be {@code null}
+     * @return {@code true} if the arrays are equal
+     * @deprecated this method has been replaced by {@code java.util.Objects.deepEquals(Object, Object)} and will be
+     * removed from future releases.
      */
-    public static boolean contains(final long[] array, final long valueToFind) {
-        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
+    @Deprecated
+    public static boolean isEquals(final Object array1, final Object array2) {
+        return new EqualsBuilder().append(array1, array2).isEquals();
     }
 
-    // int IndexOf
-    //-----------------------------------------------------------------------
     /**
-     * <p>Finds the index of the given value in the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks if an array of primitive booleans is not empty and not {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static int indexOf(final int[] array, final int valueToFind) {
-        return indexOf(array, valueToFind, 0);
+    public static boolean isNotEmpty(final boolean[] array) {
+        return !isEmpty(array);
     }
 
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <p>Checks if an array of primitive bytes is not empty and not {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static int indexOf(final int[] array, final int valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            startIndex = 0;
-        }
-        for (int i = startIndex; i < array.length; i++) {
-            if (valueToFind == array[i]) {
-                return i;
-            }
-        }
-        return INDEX_NOT_FOUND;
+    public static boolean isNotEmpty(final byte[] array) {
+        return !isEmpty(array);
     }
 
     /**
-     * Finds the indices of the given value in the array.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>Checks if an array of primitive chars is not empty and not {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static BitSet indexesOf(final int[] array, final int valueToFind) {
-        return indexesOf(array, valueToFind, 0);
+    public static boolean isNotEmpty(final char[] array) {
+        return !isEmpty(array);
     }
 
     /**
-     * Finds the indices of the given value in the array starting at the given index.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet.</p>
+     * <p>Checks if an array of primitive doubles is not empty and not {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static BitSet indexesOf(final int[] array, final int valueToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
-
-        if (array == null) {
-            return bitSet;
-        }
-
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
-            }
-
-            bitSet.set(startIndex);
-            ++startIndex;
-        }
-
-        return bitSet;
-    }
+    public static boolean isNotEmpty(final double[] array) {
+        return !isEmpty(array);
+    }
 
     /**
-     * <p>Finds the last index of the given value within the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks if an array of primitive floats is not empty and not {@code null}.
      *
-     * @param array  the array to traverse backwards looking for the object, may be {@code null}
-     * @param valueToFind  the object to find
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static int lastIndexOf(final int[] array, final int valueToFind) {
-        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
+    public static boolean isNotEmpty(final float[] array) {
+        return !isEmpty(array);
     }
 
     /**
-     * <p>Finds the last index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
-     * array length will search from the end of the array.
+     * <p>Checks if an array of primitive ints is not empty and not {@code null}.
      *
-     * @param array  the array to traverse for looking for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the start index to traverse backwards from
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static int lastIndexOf(final int[] array, final int valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            return INDEX_NOT_FOUND;
-        } else if (startIndex >= array.length) {
-            startIndex = array.length - 1;
-        }
-        for (int i = startIndex; i >= 0; i--) {
-            if (valueToFind == array[i]) {
-                return i;
-            }
-        }
-        return INDEX_NOT_FOUND;
+    public static boolean isNotEmpty(final int[] array) {
+        return !isEmpty(array);
     }
 
     /**
-     * <p>Checks if the value is in the given array.
-     *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     * <p>Checks if an array of primitive longs is not empty and not {@code null}.
      *
-     * @param array  the array to search through
-     * @param valueToFind  the value to find
-     * @return {@code true} if the array contains the object
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static boolean contains(final int[] array, final int valueToFind) {
-        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
+    public static boolean isNotEmpty(final long[] array) {
+        return !isEmpty(array);
     }
 
-    // short IndexOf
-    //-----------------------------------------------------------------------
     /**
-     * <p>Finds the index of the given value in the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks if an array of primitive shorts is not empty and not {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static int indexOf(final short[] array, final short valueToFind) {
-        return indexOf(array, valueToFind, 0);
+    public static boolean isNotEmpty(final short[] array) {
+        return !isEmpty(array);
     }
 
+    // ----------------------------------------------------------------------
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <p>Checks if an array of Objects is not empty and not {@code null}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param <T> the component type of the array
+     * @param array  the array to test
+     * @return {@code true} if the array is not empty and not {@code null}
+     * @since 2.5
      */
-    public static int indexOf(final short[] array, final short valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            startIndex = 0;
-        }
-        for (int i = startIndex; i < array.length; i++) {
-            if (valueToFind == array[i]) {
-                return i;
-            }
-        }
-        return INDEX_NOT_FOUND;
-    }
+     public static <T> boolean isNotEmpty(final T[] array) {
+         return !isEmpty(array);
+     }
 
     /**
-     * Finds the indices of the given value in the array.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static BitSet indexesOf(final short[] array, final short valueToFind) {
-        return indexesOf(array, valueToFind, 0);
+    public static boolean isSameLength(final boolean[] array1, final boolean[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
     /**
-     * Finds the indices of the given value in the array starting at the given index.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet.</p>
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static BitSet indexesOf(final short[] array, final short valueToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
-
-        if (array == null) {
-            return bitSet;
-        }
-
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
-            }
-
-            bitSet.set(startIndex);
-            ++startIndex;
-        }
-
-        return bitSet;
+    public static boolean isSameLength(final byte[] array1, final byte[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
     /**
-     * <p>Finds the last index of the given value within the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * @param array  the array to traverse backwards looking for the object, may be {@code null}
-     * @param valueToFind  the object to find
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static int lastIndexOf(final short[] array, final short valueToFind) {
-        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
+    public static boolean isSameLength(final char[] array1, final char[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
     /**
-     * <p>Finds the last index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
-     * array length will search from the end of the array.
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * @param array  the array to traverse for looking for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the start index to traverse backwards from
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static int lastIndexOf(final short[] array, final short valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            return INDEX_NOT_FOUND;
-        } else if (startIndex >= array.length) {
-            startIndex = array.length - 1;
-        }
-        for (int i = startIndex; i >= 0; i--) {
-            if (valueToFind == array[i]) {
-                return i;
-            }
-        }
-        return INDEX_NOT_FOUND;
+    public static boolean isSameLength(final double[] array1, final double[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
     /**
-     * <p>Checks if the value is in the given array.
-     *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * @param array  the array to search through
-     * @param valueToFind  the value to find
-     * @return {@code true} if the array contains the object
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static boolean contains(final short[] array, final short valueToFind) {
-        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
+    public static boolean isSameLength(final float[] array1, final float[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
-    // char IndexOf
-    //-----------------------------------------------------------------------
     /**
-     * <p>Finds the index of the given value in the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
-     * @since 2.1
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static int indexOf(final char[] array, final char valueToFind) {
-        return indexOf(array, valueToFind, 0);
+    public static boolean isSameLength(final int[] array1, final int[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
-     * @since 2.1
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static int indexOf(final char[] array, final char valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            startIndex = 0;
-        }
-        for (int i = startIndex; i < array.length; i++) {
-            if (valueToFind == array[i]) {
-                return i;
-            }
-        }
-        return INDEX_NOT_FOUND;
+    public static boolean isSameLength(final long[] array1, final long[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
+    // Is same length
+    //-----------------------------------------------------------------------
     /**
-     * Finds the indices of the given value in the array.
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>Any multi-dimensional aspects of the arrays are ignored.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static BitSet indexesOf(final char[] array, final char valueToFind) {
-        return indexesOf(array, valueToFind, 0);
+    public static boolean isSameLength(final Object[] array1, final Object[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
     /**
-     * Finds the indices of the given value in the array starting at the given index.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet.</p>
+     * <p>Checks whether two arrays are the same length, treating
+     * {@code null} arrays as length {@code 0}.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array1 the first array, may be {@code null}
+     * @param array2 the second array, may be {@code null}
+     * @return {@code true} if length of arrays matches, treating
+     *  {@code null} as an empty array
      */
-    public static BitSet indexesOf(final char[] array, final char valueToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
-
-        if (array == null) {
-            return bitSet;
-        }
-
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
-            }
-
-            bitSet.set(startIndex);
-            ++startIndex;
-        }
-
-        return bitSet;
+    public static boolean isSameLength(final short[] array1, final short[] array2) {
+        return getLength(array1) == getLength(array2);
     }
 
     /**
-     * <p>Finds the last index of the given value within the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>Checks whether two arrays are the same type taking into account
+     * multi-dimensional arrays.
      *
-     * @param array  the array to traverse backwards looking for the object, may be {@code null}
-     * @param valueToFind  the object to find
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
-     * @since 2.1
+     * @param array1 the first array, must not be {@code null}
+     * @param array2 the second array, must not be {@code null}
+     * @return {@code true} if type of arrays matches
+     * @throws IllegalArgumentException if either array is {@code null}
      */
-    public static int lastIndexOf(final char[] array, final char valueToFind) {
-        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
+    public static boolean isSameType(final Object array1, final Object array2) {
+        if (array1 == null || array2 == null) {
+            throw new IllegalArgumentException("The Array must not be null");
+        }
+        return array1.getClass().getName().equals(array2.getClass().getName());
     }
 
     /**
-     * <p>Finds the last index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
-     * array length will search from the end of the array.
+     * <p>This method checks whether the provided array is sorted according to natural ordering
+     * ({@code false} before {@code true}).
      *
-     * @param array  the array to traverse for looking for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the start index to traverse backwards from
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
-     * @since 2.1
+     * @param array the array to check
+     * @return whether the array is sorted according to natural ordering
+     * @since 3.4
      */
-    public static int lastIndexOf(final char[] array, final char valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            return INDEX_NOT_FOUND;
-        } else if (startIndex >= array.length) {
-            startIndex = array.length - 1;
+    public static boolean isSorted(final boolean[] array) {
+        if (array == null || array.length < 2) {
+            return true;
         }
-        for (int i = startIndex; i >= 0; i--) {
-            if (valueToFind == array[i]) {
-                return i;
+
+        boolean previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final boolean current = array[i];
+            if (BooleanUtils.compare(previous, current) > 0) {
+                return false;
             }
+
+            previous = current;
         }
-        return INDEX_NOT_FOUND;
+        return true;
     }
 
     /**
-     * <p>Checks if the value is in the given array.
-     *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     * <p>This method checks whether the provided array is sorted according to natural ordering.
      *
-     * @param array  the array to search through
-     * @param valueToFind  the value to find
-     * @return {@code true} if the array contains the object
-     * @since 2.1
+     * @param array the array to check
+     * @return whether the array is sorted according to natural ordering
+     * @since 3.4
      */
-    public static boolean contains(final char[] array, final char valueToFind) {
-        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
-    }
+    public static boolean isSorted(final byte[] array) {
+        if (array == null || array.length < 2) {
+            return true;
+        }
 
-    // byte IndexOf
-    //-----------------------------------------------------------------------
-    /**
-     * <p>Finds the index of the given value in the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
-     */
-    public static int indexOf(final byte[] array, final byte valueToFind) {
-        return indexOf(array, valueToFind, 0);
+        byte previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final byte current = array[i];
+            if (NumberUtils.compare(previous, current) > 0) {
+                return false;
+            }
+
+            previous = current;
+        }
+        return true;
     }
 
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <p>This method checks whether the provided array is sorted according to natural ordering.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @param array the array to check
+     * @return whether the array is sorted according to natural ordering
+     * @since 3.4
      */
-    public static int indexOf(final byte[] array, final byte valueToFind, int startIndex) {
-        if (array == null) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            startIndex = 0;
+    public static boolean isSorted(final char[] array) {
+        if (array == null || array.length < 2) {
+            return true;
         }
-        for (int i = startIndex; i < array.length; i++) {
-            if (valueToFind == array[i]) {
-                return i;
+
+        char previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final char current = array[i];
+            if (CharUtils.compare(previous, current) > 0) {
+                return false;
             }
+
+            previous = current;
         }
-        return INDEX_NOT_FOUND;
+        return true;
     }
 
     /**
-     * Finds the indices of the given value in the array.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>This method checks whether the provided array is sorted according to natural ordering.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array the array to check
+     * @return whether the array is sorted according to natural ordering
+     * @since 3.4
      */
-    public static BitSet indexesOf(final byte[] array, final byte valueToFind) {
-        return indexesOf(array, valueToFind, 0);
+    public static boolean isSorted(final double[] array) {
+        if (array == null || array.length < 2) {
+            return true;
+        }
+
+        double previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final double current = array[i];
+            if (Double.compare(previous, current) > 0) {
+                return false;
+            }
+
+            previous = current;
+        }
+        return true;
     }
 
     /**
-     * Finds the indices of the given value in the array starting at the given index.
+     * <p>This method checks whether the provided array is sorted according to natural ordering.
      *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * @param array the array to check
+     * @return whether the array is sorted according to natural ordering
+     * @since 3.4
+     */
+    public static boolean isSorted(final float[] array) {
+        if (array == null || array.length < 2) {
+            return true;
+        }
+
+        float previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final float current = array[i];
+            if (Float.compare(previous, current) > 0) {
+                return false;
+            }
+
+            previous = current;
+        }
+        return true;
+    }
+
+    /**
+     * <p>This method checks whether the provided array is sorted according to natural ordering.
      *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet.</p>
+     * @param array the array to check
+     * @return whether the array is sorted according to natural ordering
+     * @since 3.4
+     */
+    public static boolean isSorted(final int[] array) {
+        if (array == null || array.length < 2) {
+            return true;
+        }
+
+        int previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final int current = array[i];
+            if (NumberUtils.compare(previous, current) > 0) {
+                return false;
+            }
+
+            previous = current;
+        }
+        return true;
+    }
+
+    /**
+     * <p>This method checks whether the provided array is sorted according to natural ordering.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array the array to check
+     * @return whether the array is sorted according to natural ordering
+     * @since 3.4
      */
-    public static BitSet indexesOf(final byte[] array, final byte valueToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
+    public static boolean isSorted(final long[] array) {
+        if (array == null || array.length < 2) {
+            return true;
+        }
 
-        if (array == null) {
-            return bitSet;
+        long previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final long current = array[i];
+            if (NumberUtils.compare(previous, current) > 0) {
+                return false;
+            }
+
+            previous = current;
         }
+        return true;
+    }
 
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex);
+    /**
+     * <p>This method checks whether the provided array is sorted according to natural ordering.
+     *
+     * @param array the array to check
+     * @return whether the array is sorted according to natural ordering
+     * @since 3.4
+     */
+    public static boolean isSorted(final short[] array) {
+        if (array == null || array.length < 2) {
+            return true;
+        }
 
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
+        short previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final short current = array[i];
+            if (NumberUtils.compare(previous, current) > 0) {
+                return false;
             }
 
-            bitSet.set(startIndex);
-            ++startIndex;
+            previous = current;
+        }
+        return true;
+    }
+
+    /**
+     * <p>This method checks whether the provided array is sorted according to the class's
+     * {@code compareTo} method.
+     *
+     * @param array the array to check
+     * @param <T> the datatype of the array to check, it must implement {@code Comparable}
+     * @return whether the array is sorted
+     * @since 3.4
+     */
+    public static <T extends Comparable<? super T>> boolean isSorted(final T[] array) {
+        return isSorted(array, (o1, o2) -> o1.compareTo(o2));
+    }
+
+    /**
+     * <p>This method checks whether the provided array is sorted according to the provided {@code Comparator}.
+     *
+     * @param array the array to check
+     * @param comparator the {@code Comparator} to compare over
+     * @param <T> the datatype of the array
+     * @return whether the array is sorted
+     * @since 3.4
+     */
+    public static <T> boolean isSorted(final T[] array, final Comparator<T> comparator) {
+        if (comparator == null) {
+            throw new IllegalArgumentException("Comparator should not be null.");
         }
 
-        return bitSet;
+        if (array == null || array.length < 2) {
+            return true;
+        }
+
+        T previous = array[0];
+        final int n = array.length;
+        for (int i = 1; i < n; i++) {
+            final T current = array[i];
+            if (comparator.compare(previous, current) > 0) {
+                return false;
+            }
+
+            previous = current;
+        }
+        return true;
     }
 
     /**
      * <p>Finds the last index of the given value within the array.
      *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) if
+     * {@code null} array input.
      *
      * @param array  the array to traverse backwards looking for the object, may be {@code null}
      * @param valueToFind  the object to find
      * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int lastIndexOf(final byte[] array, final byte valueToFind) {
+    public static int lastIndexOf(final boolean[] array, final boolean valueToFind) {
         return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
     }
 
@@ -4109,8 +3690,8 @@ public class ArrayUtils {
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
-     * array length will search from the end of the array.
+     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than
+     * the array length will search from the end of the array.
      *
      * @param array  the array to traverse for looking for the object, may be {@code null}
      * @param valueToFind  the value to find
@@ -4118,8 +3699,8 @@ public class ArrayUtils {
      * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int lastIndexOf(final byte[] array, final byte valueToFind, int startIndex) {
-        if (array == null) {
+    public static int lastIndexOf(final boolean[] array, final boolean valueToFind, int startIndex) {
+        if (isEmpty(array)) {
             return INDEX_NOT_FOUND;
         }
         if (startIndex < 0) {
@@ -4136,73 +3717,43 @@ public class ArrayUtils {
     }
 
     /**
-     * <p>Checks if the value is in the given array.
-     *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
-     *
-     * @param array  the array to search through
-     * @param valueToFind  the value to find
-     * @return {@code true} if the array contains the object
-     */
-    public static boolean contains(final byte[] array, final byte valueToFind) {
-        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
-    }
-
-    // double IndexOf
-    //-----------------------------------------------------------------------
-    /**
-     * <p>Finds the index of the given value in the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
-     */
-    public static int indexOf(final double[] array, final double valueToFind) {
-        return indexOf(array, valueToFind, 0);
-    }
-
-    /**
-     * <p>Finds the index of the given value within a given tolerance in the array.
-     * This method will return the index of the first value which falls between the region
-     * defined by valueToFind - tolerance and valueToFind + tolerance.
+     * <p>Finds the last index of the given value within the array.
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param tolerance tolerance of the search
-     * @return the index of the value within the array,
+     * @param array  the array to traverse backwards looking for the object, may be {@code null}
+     * @param valueToFind  the object to find
+     * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int indexOf(final double[] array, final double valueToFind, final double tolerance) {
-        return indexOf(array, valueToFind, 0, tolerance);
+    public static int lastIndexOf(final byte[] array, final byte valueToFind) {
+        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
     }
 
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
+     * <p>Finds the last index of the given value in the array starting at the given index.
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
+     * array length will search from the end of the array.
      *
-     * @param array  the array to search through for the object, may be {@code null}
+     * @param array  the array to traverse for looking for the object, may be {@code null}
      * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return the index of the value within the array,
+     * @param startIndex  the start index to traverse backwards from
+     * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int indexOf(final double[] array, final double valueToFind, int startIndex) {
-        if (isEmpty(array)) {
+    public static int lastIndexOf(final byte[] array, final byte valueToFind, int startIndex) {
+        if (array == null) {
             return INDEX_NOT_FOUND;
         }
         if (startIndex < 0) {
-            startIndex = 0;
+            return INDEX_NOT_FOUND;
+        } else if (startIndex >= array.length) {
+            startIndex = array.length - 1;
         }
-        for (int i = startIndex; i < array.length; i++) {
+        for (int i = startIndex; i >= 0; i--) {
             if (valueToFind == array[i]) {
                 return i;
             }
@@ -4211,152 +3762,50 @@ public class ArrayUtils {
     }
 
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
-     * This method will return the index of the first value which falls between the region
-     * defined by valueToFind - tolerance and valueToFind + tolerance.
+     * <p>Finds the last index of the given value within the array.
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @param tolerance tolerance of the search
-     * @return the index of the value within the array,
+     * @param array  the array to traverse backwards looking for the object, may be {@code null}
+     * @param valueToFind  the object to find
+     * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @since 2.1
      */
-    public static int indexOf(final double[] array, final double valueToFind, int startIndex, final double tolerance) {
-        if (isEmpty(array)) {
-            return INDEX_NOT_FOUND;
-        }
-        if (startIndex < 0) {
-            startIndex = 0;
-        }
-        final double min = valueToFind - tolerance;
-        final double max = valueToFind + tolerance;
-        for (int i = startIndex; i < array.length; i++) {
-            if (array[i] >= min && array[i] <= max) {
-                return i;
-            }
-        }
-        return INDEX_NOT_FOUND;
-    }
-
-    /**
-     * Finds the indices of the given value in the array.
-     *
-     * <p>This method returns empty BitSet for a {@code null} input array.</p>
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
-     */
-    public static BitSet indexesOf(final double[] array, final double valueToFind) {
-        return indexesOf(array, valueToFind, 0);
-    }
-
-    /**
-     * Finds the indices of the given value within a given tolerance in the array.
-     *
-     * <p>
-     * This method will return all the indices of the value which fall between the region
-     * defined by valueToFind - tolerance and valueToFind + tolerance, each time between the nearest integers.
-     * </p>
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param tolerance tolerance of the search
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
-     */
-    public static BitSet indexesOf(final double[] array, final double valueToFind, final double tolerance) {
-        return indexesOf(array, valueToFind, 0, tolerance);
+    public static int lastIndexOf(final char[] array, final char valueToFind) {
+        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
     }
 
-
     /**
-     * Finds the indices of the given value in the array starting at the given index.
+     * <p>Finds the last index of the given value in the array starting at the given index.
      *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet.</p>
+     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
+     * array length will search from the end of the array.
      *
-     * @param array  the array to search through for the object, may be {@code null}
+     * @param array  the array to traverse for looking for the object, may be {@code null}
      * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param startIndex  the start index to traverse backwards from
+     * @return the last index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
+     * @since 2.1
      */
-    public static BitSet indexesOf(final double[] array, final double valueToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
-
+    public static int lastIndexOf(final char[] array, final char valueToFind, int startIndex) {
         if (array == null) {
-            return bitSet;
-        }
-
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
-            }
-
-            bitSet.set(startIndex);
-            ++startIndex;
+            return INDEX_NOT_FOUND;
         }
-
-        return bitSet;
-    }
-
-    /**
-     * Finds the indices of the given value in the array starting at the given index.
-     *
-     * <p>
-     * This method will return the indices of the values which fall between the region
-     * defined by valueToFind - tolerance and valueToFind + tolerance, between the nearest integers.
-     * </p>
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet.</p>
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @param tolerance tolerance of the search
-     * @return a BitSet of the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
-     */
-    public static BitSet indexesOf(final double[] array, final double valueToFind, int startIndex, final double tolerance) {
-        BitSet bitSet = new BitSet();
-
-        if (array == null) {
-            return bitSet;
+        if (startIndex < 0) {
+            return INDEX_NOT_FOUND;
+        } else if (startIndex >= array.length) {
+            startIndex = array.length - 1;
         }
-
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex, tolerance);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
+        for (int i = startIndex; i >= 0; i--) {
+            if (valueToFind == array[i]) {
+                return i;
             }
-
-            bitSet.set(startIndex);
-            ++startIndex;
         }
-
-        return bitSet;
+        return INDEX_NOT_FOUND;
     }
 
     /**
@@ -4457,74 +3906,90 @@ public class ArrayUtils {
         return INDEX_NOT_FOUND;
     }
 
+
     /**
-     * <p>Checks if the value is in the given array.
+     * <p>Finds the last index of the given value within the array.
      *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to search through
-     * @param valueToFind  the value to find
-     * @return {@code true} if the array contains the object
+     * @param array  the array to traverse backwards looking for the object, may be {@code null}
+     * @param valueToFind  the object to find
+     * @return the last index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static boolean contains(final double[] array, final double valueToFind) {
-        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
+    public static int lastIndexOf(final float[] array, final float valueToFind) {
+        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
     }
 
     /**
-     * <p>Checks if a value falling within the given tolerance is in the
-     * given array.  If the array contains a value within the inclusive range
-     * defined by (value - tolerance) to (value + tolerance).
+     * <p>Finds the last index of the given value in the array starting at the given index.
      *
-     * <p>The method returns {@code false} if a {@code null} array
-     * is passed in.
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to search
+     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
+     * array length will search from the end of the array.
+     *
+     * @param array  the array to traverse for looking for the object, may be {@code null}
      * @param valueToFind  the value to find
-     * @param tolerance  the array contains the tolerance of the search
-     * @return true if value falling within tolerance is in array
+     * @param startIndex  the start index to traverse backwards from
+     * @return the last index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static boolean contains(final double[] array, final double valueToFind, final double tolerance) {
-        return indexOf(array, valueToFind, 0, tolerance) != INDEX_NOT_FOUND;
+    public static int lastIndexOf(final float[] array, final float valueToFind, int startIndex) {
+        if (isEmpty(array)) {
+            return INDEX_NOT_FOUND;
+        }
+        if (startIndex < 0) {
+            return INDEX_NOT_FOUND;
+        } else if (startIndex >= array.length) {
+            startIndex = array.length - 1;
+        }
+        for (int i = startIndex; i >= 0; i--) {
+            if (valueToFind == array[i]) {
+                return i;
+            }
+        }
+        return INDEX_NOT_FOUND;
     }
 
-    // float IndexOf
-    //-----------------------------------------------------------------------
     /**
-     * <p>Finds the index of the given value in the array.
+     * <p>Finds the last index of the given value within the array.
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return the index of the value within the array,
+     * @param array  the array to traverse backwards looking for the object, may be {@code null}
+     * @param valueToFind  the object to find
+     * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int indexOf(final float[] array, final float valueToFind) {
-        return indexOf(array, valueToFind, 0);
+    public static int lastIndexOf(final int[] array, final int valueToFind) {
+        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
     }
 
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
+     * <p>Finds the last index of the given value in the array starting at the given index.
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
+     * array length will search from the end of the array.
      *
-     * @param array  the array to search through for the object, may be {@code null}
+     * @param array  the array to traverse for looking for the object, may be {@code null}
      * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return the index of the value within the array,
+     * @param startIndex  the start index to traverse backwards from
+     * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int indexOf(final float[] array, final float valueToFind, int startIndex) {
-        if (isEmpty(array)) {
+    public static int lastIndexOf(final int[] array, final int valueToFind, int startIndex) {
+        if (array == null) {
             return INDEX_NOT_FOUND;
         }
         if (startIndex < 0) {
-            startIndex = 0;
+            return INDEX_NOT_FOUND;
+        } else if (startIndex >= array.length) {
+            startIndex = array.length - 1;
         }
-        for (int i = startIndex; i < array.length; i++) {
+        for (int i = startIndex; i >= 0; i--) {
             if (valueToFind == array[i]) {
                 return i;
             }
@@ -4533,74 +3998,23 @@ public class ArrayUtils {
     }
 
     /**
-     * Finds the indices of the given value in the array.
+     * <p>Finds the last index of the given value within the array.
      *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
+     * @param array  the array to traverse backwards looking for the object, may be {@code null}
+     * @param valueToFind  the object to find
+     * @return the last index of the value within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static BitSet indexesOf(final float[] array, final float valueToFind) {
-        return indexesOf(array, valueToFind, 0);
+    public static int lastIndexOf(final long[] array, final long valueToFind) {
+        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
     }
 
     /**
-     * Finds the indices of the given value in the array starting at the given index.
+     * <p>Finds the last index of the given value in the array starting at the given index.
      *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return empty BitSet.</p>
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
-     */
-    public static BitSet indexesOf(final float[] array, final float valueToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
-
-        if (array == null) {
-            return bitSet;
-        }
-
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
-            }
-
-            bitSet.set(startIndex);
-            ++startIndex;
-        }
-
-        return bitSet;
-    }
-
-    /**
-     * <p>Finds the last index of the given value within the array.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
-     *
-     * @param array  the array to traverse backwards looking for the object, may be {@code null}
-     * @param valueToFind  the object to find
-     * @return the last index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
-     */
-    public static int lastIndexOf(final float[] array, final float valueToFind) {
-        return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
-    }
-
-    /**
-     * <p>Finds the last index of the given value in the array starting at the given index.
-     *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
      * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
      * array length will search from the end of the array.
@@ -4611,8 +4025,8 @@ public class ArrayUtils {
      * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int lastIndexOf(final float[] array, final float valueToFind, int startIndex) {
-        if (isEmpty(array)) {
+    public static int lastIndexOf(final long[] array, final long valueToFind, int startIndex) {
+        if (array == null) {
             return INDEX_NOT_FOUND;
         }
         if (startIndex < 0) {
@@ -4629,128 +4043,69 @@ public class ArrayUtils {
     }
 
     /**
-     * <p>Checks if the value is in the given array.
-     *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
-     *
-     * @param array  the array to search through
-     * @param valueToFind  the value to find
-     * @return {@code true} if the array contains the object
-     */
-    public static boolean contains(final float[] array, final float valueToFind) {
-        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
-    }
-
-    // boolean IndexOf
-    //-----------------------------------------------------------------------
-    /**
-     * <p>Finds the index of the given value in the array.
+     * <p>Finds the last index of the given object within the array.
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return the index of the value within the array,
+     * @param array  the array to traverse backwards looking for the object, may be {@code null}
+     * @param objectToFind  the object to find, may be {@code null}
+     * @return the last index of the object within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int indexOf(final boolean[] array, final boolean valueToFind) {
-        return indexOf(array, valueToFind, 0);
+    public static int lastIndexOf(final Object[] array, final Object objectToFind) {
+        return lastIndexOf(array, objectToFind, Integer.MAX_VALUE);
     }
 
     /**
-     * <p>Finds the index of the given value in the array starting at the given index.
+     * <p>Finds the last index of the given object in the array starting at the given index.
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).
+     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than
+     * the array length will search from the end of the array.
      *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return the index of the value within the array,
-     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null}
-     *  array input
+     * @param array  the array to traverse for looking for the object, may be {@code null}
+     * @param objectToFind  the object to find, may be {@code null}
+     * @param startIndex  the start index to traverse backwards from
+     * @return the last index of the object within the array,
+     *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int indexOf(final boolean[] array, final boolean valueToFind, int startIndex) {
-        if (isEmpty(array)) {
+    public static int lastIndexOf(final Object[] array, final Object objectToFind, int startIndex) {
+        if (array == null) {
             return INDEX_NOT_FOUND;
         }
         if (startIndex < 0) {
-            startIndex = 0;
+            return INDEX_NOT_FOUND;
+        } else if (startIndex >= array.length) {
+            startIndex = array.length - 1;
         }
-        for (int i = startIndex; i < array.length; i++) {
-            if (valueToFind == array[i]) {
-                return i;
+        if (objectToFind == null) {
+            for (int i = startIndex; i >= 0; i--) {
+                if (array[i] == null) {
+                    return i;
+                }
             }
-        }
-        return INDEX_NOT_FOUND;
-    }
-
-    /**
-     * Finds the indices of the given value in the array.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @return a BitSet of all the the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null} array input
-     * @since 3.10
-     */
-    public static BitSet indexesOf(final boolean[] array, final boolean valueToFind) {
-        return indexesOf(array, valueToFind, 0);
-    }
-
-    /**
-     * Finds the indices of the given value in the array starting at the given index.
-     *
-     * <p>This method returns an empty BitSet for a {@code null} input array.</p>
-     *
-     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
-     * length will return an empty BitSet ({@code -1}).</p>
-     *
-     * @param array  the array to search through for the object, may be {@code null}
-     * @param valueToFind  the value to find
-     * @param startIndex  the index to start searching at
-     * @return a BitSet of all the indices of the value within the array,
-     *  an empty BitSet if not found or {@code null}
-     *  array input
-     * @since 3.10
-     */
-    public static BitSet indexesOf(final boolean[] array, final boolean valueToFind, int startIndex) {
-        BitSet bitSet = new BitSet();
-
-        if (array == null) {
-            return bitSet;
-        }
-
-        while (startIndex < array.length) {
-            startIndex = indexOf(array, valueToFind, startIndex);
-
-            if (startIndex == INDEX_NOT_FOUND) {
-                break;
+        } else if (array.getClass().getComponentType().isInstance(objectToFind)) {
+            for (int i = startIndex; i >= 0; i--) {
+                if (objectToFind.equals(array[i])) {
+                    return i;
+                }
             }
-
-            bitSet.set(startIndex);
-            ++startIndex;
         }
-
-        return bitSet;
+        return INDEX_NOT_FOUND;
     }
 
     /**
      * <p>Finds the last index of the given value within the array.
      *
-     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) if
-     * {@code null} array input.
+     * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
      * @param array  the array to traverse backwards looking for the object, may be {@code null}
      * @param valueToFind  the object to find
      * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int lastIndexOf(final boolean[] array, final boolean valueToFind) {
+    public static int lastIndexOf(final short[] array, final short valueToFind) {
         return lastIndexOf(array, valueToFind, Integer.MAX_VALUE);
     }
 
@@ -4759,8 +4114,8 @@ public class ArrayUtils {
      *
      * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.
      *
-     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than
-     * the array length will search from the end of the array.
+     * <p>A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the
+     * array length will search from the end of the array.
      *
      * @param array  the array to traverse for looking for the object, may be {@code null}
      * @param valueToFind  the value to find
@@ -4768,8 +4123,8 @@ public class ArrayUtils {
      * @return the last index of the value within the array,
      *  {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input
      */
-    public static int lastIndexOf(final boolean[] array, final boolean valueToFind, int startIndex) {
-        if (isEmpty(array)) {
+    public static int lastIndexOf(final short[] array, final short valueToFind, int startIndex) {
+        if (array == null) {
             return INDEX_NOT_FOUND;
         }
         if (startIndex < 0) {
@@ -4786,4598 +4141,5243 @@ public class ArrayUtils {
     }
 
     /**
-     * <p>Checks if the value is in the given array.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>The method returns {@code false} if a {@code null} array is passed in.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  the array to search through
-     * @param valueToFind  the value to find
-     * @return {@code true} if the array contains the object
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static boolean contains(final boolean[] array, final boolean valueToFind) {
-        return indexOf(array, valueToFind) != INDEX_NOT_FOUND;
+    public static boolean[] nullToEmpty(final boolean[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_BOOLEAN_ARRAY;
+        }
+        return array;
     }
 
-    // Primitive/Object array converters
-    // ----------------------------------------------------------------------
-
-    // Character array converters
-    // ----------------------------------------------------------------------
     /**
-     * <p>Converts an array of object Characters to primitives.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Character} array, may be {@code null}
-     * @return a {@code char} array, {@code null} if null array input
-     * @throws NullPointerException if array content is {@code null}
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static char[] toPrimitive(final Character[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_CHAR_ARRAY;
-        }
-        final char[] result = new char[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = array[i].charValue();
+    public static Boolean[] nullToEmpty(final Boolean[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_BOOLEAN_OBJECT_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of object Character to primitives handling {@code null}.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Character} array, may be {@code null}
-     * @param valueForNull  the value to insert if {@code null} found
-     * @return a {@code char} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static char[] toPrimitive(final Character[] array, final char valueForNull) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_CHAR_ARRAY;
-        }
-        final char[] result = new char[array.length];
-        for (int i = 0; i < array.length; i++) {
-            final Character b = array[i];
-            result[i] = (b == null ? valueForNull : b.charValue());
+    public static byte[] nullToEmpty(final byte[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_BYTE_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of primitive chars to objects.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array a {@code char} array
-     * @return a {@code Character} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static Character[] toObject(final char[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_CHARACTER_OBJECT_ARRAY;
-        }
-        final Character[] result = new Character[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = Character.valueOf(array[i]);
+    public static Byte[] nullToEmpty(final Byte[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_BYTE_OBJECT_ARRAY;
         }
-        return result;
-     }
+        return array;
+    }
 
-    // Long array converters
-    // ----------------------------------------------------------------------
     /**
-     * <p>Converts an array of object Longs to primitives.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Long} array, may be {@code null}
-     * @return a {@code long} array, {@code null} if null array input
-     * @throws NullPointerException if array content is {@code null}
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static long[] toPrimitive(final Long[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_LONG_ARRAY;
-        }
-        final long[] result = new long[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = array[i].longValue();
+    public static char[] nullToEmpty(final char[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_CHAR_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of object Long to primitives handling {@code null}.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Long} array, may be {@code null}
-     * @param valueForNull  the value to insert if {@code null} found
-     * @return a {@code long} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static long[] toPrimitive(final Long[] array, final long valueForNull) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_LONG_ARRAY;
-        }
-        final long[] result = new long[array.length];
-        for (int i = 0; i < array.length; i++) {
-            final Long b = array[i];
-            result[i] = (b == null ? valueForNull : b.longValue());
+    public static Character[] nullToEmpty(final Character[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_CHARACTER_OBJECT_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of primitive longs to objects.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code long} array
-     * @return a {@code Long} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 3.2
      */
-    public static Long[] toObject(final long[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_LONG_OBJECT_ARRAY;
-        }
-        final Long[] result = new Long[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = Long.valueOf(array[i]);
+    public static Class<?>[] nullToEmpty(final Class<?>[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_CLASS_ARRAY;
         }
-        return result;
+        return array;
     }
 
-    // Int array converters
-    // ----------------------------------------------------------------------
     /**
-     * <p>Converts an array of object Integers to primitives.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Integer} array, may be {@code null}
-     * @return an {@code int} array, {@code null} if null array input
-     * @throws NullPointerException if array content is {@code null}
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static int[] toPrimitive(final Integer[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_INT_ARRAY;
-        }
-        final int[] result = new int[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = array[i].intValue();
+    public static double[] nullToEmpty(final double[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_DOUBLE_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of object Integer to primitives handling {@code null}.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Integer} array, may be {@code null}
-     * @param valueForNull  the value to insert if {@code null} found
-     * @return an {@code int} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static int[] toPrimitive(final Integer[] array, final int valueForNull) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_INT_ARRAY;
-        }
-        final int[] result = new int[array.length];
-        for (int i = 0; i < array.length; i++) {
-            final Integer b = array[i];
-            result[i] = (b == null ? valueForNull : b.intValue());
+    public static Double[] nullToEmpty(final Double[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_DOUBLE_OBJECT_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of primitive ints to objects.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  an {@code int} array
-     * @return an {@code Integer} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static Integer[] toObject(final int[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_INTEGER_OBJECT_ARRAY;
-        }
-        final Integer[] result = new Integer[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = Integer.valueOf(array[i]);
+    public static float[] nullToEmpty(final float[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_FLOAT_ARRAY;
         }
-        return result;
+        return array;
     }
 
-    // Short array converters
-    // ----------------------------------------------------------------------
     /**
-     * <p>Converts an array of object Shorts to primitives.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Short} array, may be {@code null}
-     * @return a {@code byte} array, {@code null} if null array input
-     * @throws NullPointerException if array content is {@code null}
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static short[] toPrimitive(final Short[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_SHORT_ARRAY;
-        }
-        final short[] result = new short[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = array[i].shortValue();
+    public static Float[] nullToEmpty(final Float[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_FLOAT_OBJECT_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of object Short to primitives handling {@code null}.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Short} array, may be {@code null}
-     * @param valueForNull  the value to insert if {@code null} found
-     * @return a {@code byte} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static short[] toPrimitive(final Short[] array, final short valueForNull) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_SHORT_ARRAY;
-        }
-        final short[] result = new short[array.length];
-        for (int i = 0; i < array.length; i++) {
-            final Short b = array[i];
-            result[i] = (b == null ? valueForNull : b.shortValue());
+    public static int[] nullToEmpty(final int[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_INT_ARRAY;
         }
-        return result;
+        return array;
     }
 
+    // Primitive/Object array converters
+    // ----------------------------------------------------------------------
+
     /**
-     * <p>Converts an array of primitive shorts to objects.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code short} array
-     * @return a {@code Short} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static Short[] toObject(final short[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_SHORT_OBJECT_ARRAY;
-        }
-        final Short[] result = new Short[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = Short.valueOf(array[i]);
+    public static Integer[] nullToEmpty(final Integer[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_INTEGER_OBJECT_ARRAY;
         }
-        return result;
+        return array;
     }
 
-    // Byte array converters
-    // ----------------------------------------------------------------------
     /**
-     * <p>Converts an array of object Bytes to primitives.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Byte} array, may be {@code null}
-     * @return a {@code byte} array, {@code null} if null array input
-     * @throws NullPointerException if array content is {@code null}
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static byte[] toPrimitive(final Byte[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_BYTE_ARRAY;
-        }
-        final byte[] result = new byte[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = array[i].byteValue();
+    public static long[] nullToEmpty(final long[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_LONG_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of object Bytes to primitives handling {@code null}.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Byte} array, may be {@code null}
-     * @param valueForNull  the value to insert if {@code null} found
-     * @return a {@code byte} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static byte[] toPrimitive(final Byte[] array, final byte valueForNull) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_BYTE_ARRAY;
-        }
-        final byte[] result = new byte[array.length];
-        for (int i = 0; i < array.length; i++) {
-            final Byte b = array[i];
-            result[i] = (b == null ? valueForNull : b.byteValue());
+    public static Long[] nullToEmpty(final Long[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_LONG_OBJECT_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of primitive bytes to objects.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code byte} array
-     * @return a {@code Byte} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static Byte[] toObject(final byte[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_BYTE_OBJECT_ARRAY;
-        }
-        final Byte[] result = new Byte[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = Byte.valueOf(array[i]);
+    public static Object[] nullToEmpty(final Object[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_OBJECT_ARRAY;
         }
-        return result;
+        return array;
     }
 
-    // Double array converters
-    // ----------------------------------------------------------------------
     /**
-     * <p>Converts an array of object Doubles to primitives.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Double} array, may be {@code null}
-     * @return a {@code double} array, {@code null} if null array input
-     * @throws NullPointerException if array content is {@code null}
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static double[] toPrimitive(final Double[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_DOUBLE_ARRAY;
-        }
-        final double[] result = new double[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = array[i].doubleValue();
+    public static short[] nullToEmpty(final short[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_SHORT_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of object Doubles to primitives handling {@code null}.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Double} array, may be {@code null}
-     * @param valueForNull  the value to insert if {@code null} found
-     * @return a {@code double} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static double[] toPrimitive(final Double[] array, final double valueForNull) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_DOUBLE_ARRAY;
-        }
-        final double[] result = new double[array.length];
-        for (int i = 0; i < array.length; i++) {
-            final Double b = array[i];
-            result[i] = (b == null ? valueForNull : b.doubleValue());
+    public static Short[] nullToEmpty(final Short[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_SHORT_OBJECT_ARRAY;
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of primitive doubles to objects.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code double} array
-     * @return a {@code Double} array, {@code null} if null array input
+     * <p>As a memory optimizing technique an empty array passed in will be overridden with
+     * the empty {@code public static} references in this class.
+     *
+     * @param array  the array to check for {@code null} or empty
+     * @return the same array, {@code public static} empty array if {@code null} or empty input
+     * @since 2.5
      */
-    public static Double[] toObject(final double[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_DOUBLE_OBJECT_ARRAY;
-        }
-        final Double[] result = new Double[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = Double.valueOf(array[i]);
+    public static String[] nullToEmpty(final String[] array) {
+        if (isEmpty(array)) {
+            return EMPTY_STRING_ARRAY;
         }
-        return result;
+        return array;
     }
 
-    //   Float array converters
-    // ----------------------------------------------------------------------
+    // nullToEmpty
+    //-----------------------------------------------------------------------
     /**
-     * <p>Converts an array of object Floats to primitives.
+     * <p>Defensive programming technique to change a {@code null}
+     * reference to an empty one.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns an empty array for a {@code null} input array.
      *
-     * @param array  a {@code Float} array, may be {@code null}
-     * @return a {@code float} array, {@code null} if null array input
-     * @throws NullPointerException if array content is {@code null}
+     * @param array  the array to check for {@code null} or empty
+     * @param type   the class representation of the desired array
+     * @param <T>  the class type
+     * @return the same array, {@code public static} empty array if {@code null}
+     * @throws IllegalArgumentException if the type argument is null
+     * @since 3.5
      */
-    public static float[] toPrimitive(final Float[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_FLOAT_ARRAY;
+    public static <T> T[] nullToEmpty(final T[] array, final Class<T[]> type) {
+        if (type == null) {
+            throw new IllegalArgumentException("The type must not be null");
         }
-        final float[] result = new float[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = array[i].floatValue();
+
+        if (array == null) {
+            return type.cast(Array.newInstance(type.getComponentType(), 0));
         }
-        return result;
+        return array;
     }
 
     /**
-     * <p>Converts an array of object Floats to primitives handling {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  a {@code Float} array, may be {@code null}
-     * @param valueForNull  the value to insert if {@code null} found
-     * @return a {@code float} array, {@code null} if null array input
-     */
-    public static float[] toPrimitive(final Float[] array, final float valueForNull) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_FLOAT_ARRAY;
-        }
-        final float[] result = new float[array.length];
-        for (int i = 0; i < array.length; i++) {
-            final Float b = array[i];
-            result[i] = (b == null ? valueForNull : b.floatValue());
-        }
-        return result;
-    }
-
-    /**
-     * <p>Converts an array of primitive floats to objects.
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <pre>
+     * ArrayUtils.remove([true], 0)              = []
+     * ArrayUtils.remove([true, false], 0)       = [false]
+     * ArrayUtils.remove([true, false], 1)       = [true]
+     * ArrayUtils.remove([true, true, false], 1) = [true, false]
+     * </pre>
      *
-     * @param array  a {@code float} array
-     * @return a {@code Float} array, {@code null} if null array input
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 2.1
      */
-    public static Float[] toObject(final float[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_FLOAT_OBJECT_ARRAY;
-        }
-        final Float[] result = new Float[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = Float.valueOf(array[i]);
-        }
-        return result;
+    public static boolean[] remove(final boolean[] array, final int index) {
+        return (boolean[]) remove((Object) array, index);
     }
 
     /**
-     * <p>Create an array of primitive type from an array of wrapper types.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  an array of wrapper object
-     * @return an array of the corresponding primitive type, or the original array
-     * @since 3.5
-     */
-    public static Object toPrimitive(final Object array) {
-        if (array == null) {
-            return null;
-        }
-        final Class<?> ct = array.getClass().getComponentType();
-        final Class<?> pt = ClassUtils.wrapperToPrimitive(ct);
-        if (Integer.TYPE.equals(pt)) {
-            return toPrimitive((Integer[]) array);
-        }
-        if (Long.TYPE.equals(pt)) {
-            return toPrimitive((Long[]) array);
-        }
-        if (Short.TYPE.equals(pt)) {
-            return toPrimitive((Short[]) array);
-        }
-        if (Double.TYPE.equals(pt)) {
-            return toPrimitive((Double[]) array);
-        }
-        if (Float.TYPE.equals(pt)) {
-            return toPrimitive((Float[]) array);
-        }
-        return array;
-    }
-
-    // Boolean array converters
-    // ----------------------------------------------------------------------
-    /**
-     * <p>Converts an array of object Booleans to primitives.
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <pre>
+     * ArrayUtils.remove([1], 0)          = []
+     * ArrayUtils.remove([1, 0], 0)       = [0]
+     * ArrayUtils.remove([1, 0], 1)       = [1]
+     * ArrayUtils.remove([1, 0, 1], 1)    = [1, 1]
+     * </pre>
      *
-     * @param array  a {@code Boolean} array, may be {@code null}
-     * @return a {@code boolean} array, {@code null} if null array input
-     * @throws NullPointerException if array content is {@code null}
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 2.1
      */
-    public static boolean[] toPrimitive(final Boolean[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_BOOLEAN_ARRAY;
-        }
-        final boolean[] result = new boolean[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = array[i].booleanValue();
-        }
-        return result;
+    public static byte[] remove(final byte[] array, final int index) {
+        return (byte[]) remove((Object) array, index);
     }
 
     /**
-     * <p>Converts an array of object Booleans to primitives handling {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  a {@code Boolean} array, may be {@code null}
-     * @param valueForNull  the value to insert if {@code null} found
-     * @return a {@code boolean} array, {@code null} if null array input
-     */
-    public static boolean[] toPrimitive(final Boolean[] array, final boolean valueForNull) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_BOOLEAN_ARRAY;
-        }
-        final boolean[] result = new boolean[array.length];
-        for (int i = 0; i < array.length; i++) {
-            final Boolean b = array[i];
-            result[i] = (b == null ? valueForNull : b.booleanValue());
-        }
-        return result;
-    }
-
-    /**
-     * <p>Converts an array of primitive booleans to objects.
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
-     * <p>This method returns {@code null} for a {@code null} input array.
+     * <pre>
+     * ArrayUtils.remove(['a'], 0)           = []
+     * ArrayUtils.remove(['a', 'b'], 0)      = ['b']
+     * ArrayUtils.remove(['a', 'b'], 1)      = ['a']
+     * ArrayUtils.remove(['a', 'b', 'c'], 1) = ['a', 'c']
+     * </pre>
      *
-     * @param array  a {@code boolean} array
-     * @return a {@code Boolean} array, {@code null} if null array input
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 2.1
      */
-    public static Boolean[] toObject(final boolean[] array) {
-        if (array == null) {
-            return null;
-        } else if (array.length == 0) {
-            return EMPTY_BOOLEAN_OBJECT_ARRAY;
-        }
-        final Boolean[] result = new Boolean[array.length];
-        for (int i = 0; i < array.length; i++) {
-            result[i] = (array[i] ? Boolean.TRUE : Boolean.FALSE);
-        }
-        return result;
+    public static char[] remove(final char[] array, final int index) {
+        return (char[]) remove((Object) array, index);
     }
 
-    // ----------------------------------------------------------------------
     /**
-     * <p>Checks if an array of Objects is empty or {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
+     *
+     * <pre>
+     * ArrayUtils.remove([1.1], 0)           = []
+     * ArrayUtils.remove([2.5, 6.0], 0)      = [6.0]
+     * ArrayUtils.remove([2.5, 6.0], 1)      = [2.5]
+     * ArrayUtils.remove([2.5, 6.0, 3.8], 1) = [2.5, 3.8]
+     * </pre>
+     *
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
      * @since 2.1
      */
-    public static boolean isEmpty(final Object[] array) {
-        return getLength(array) == 0;
+    public static double[] remove(final double[] array, final int index) {
+        return (double[]) remove((Object) array, index);
     }
 
     /**
-     * <p>Checks if an array of primitive longs is empty or {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
+     *
+     * <pre>
+     * ArrayUtils.remove([1.1], 0)           = []
+     * ArrayUtils.remove([2.5, 6.0], 0)      = [6.0]
+     * ArrayUtils.remove([2.5, 6.0], 1)      = [2.5]
+     * ArrayUtils.remove([2.5, 6.0, 3.8], 1) = [2.5, 3.8]
+     * </pre>
+     *
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
      * @since 2.1
      */
-    public static boolean isEmpty(final long[] array) {
-        return getLength(array) == 0;
+    public static float[] remove(final float[] array, final int index) {
+        return (float[]) remove((Object) array, index);
     }
 
     /**
-     * <p>Checks if an array of primitive ints is empty or {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
-     * @since 2.1
-     */
-    public static boolean isEmpty(final int[] array) {
-        return getLength(array) == 0;
-    }
-
-    /**
-     * <p>Checks if an array of primitive shorts is empty or {@code null}.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
-     * @since 2.1
-     */
-    public static boolean isEmpty(final short[] array) {
-        return getLength(array) == 0;
-    }
-
-    /**
-     * <p>Checks if an array of primitive chars is empty or {@code null}.
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
+     * <pre>
+     * ArrayUtils.remove([1], 0)         = []
+     * ArrayUtils.remove([2, 6], 0)      = [6]
+     * ArrayUtils.remove([2, 6], 1)      = [2]
+     * ArrayUtils.remove([2, 6, 3], 1)   = [2, 3]
+     * </pre>
+     *
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
      * @since 2.1
      */
-    public static boolean isEmpty(final char[] array) {
-        return getLength(array) == 0;
+    public static int[] remove(final int[] array, final int index) {
+        return (int[]) remove((Object) array, index);
     }
 
     /**
-     * <p>Checks if an array of primitive bytes is empty or {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
+     *
+     * <pre>
+     * ArrayUtils.remove([1], 0)         = []
+     * ArrayUtils.remove([2, 6], 0)      = [6]
+     * ArrayUtils.remove([2, 6], 1)      = [2]
+     * ArrayUtils.remove([2, 6, 3], 1)   = [2, 3]
+     * </pre>
+     *
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
      * @since 2.1
      */
-    public static boolean isEmpty(final byte[] array) {
-        return getLength(array) == 0;
+    public static long[] remove(final long[] array, final int index) {
+        return (long[]) remove((Object) array, index);
     }
 
     /**
-     * <p>Checks if an array of primitive doubles is empty or {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
+     *
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
      * @since 2.1
      */
-    public static boolean isEmpty(final double[] array) {
-        return getLength(array) == 0;
+    private static Object remove(final Object array, final int index) {
+        final int length = getLength(array);
+        if (index < 0 || index >= length) {
+            throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + length);
+        }
+
+        final Object result = Array.newInstance(array.getClass().getComponentType(), length - 1);
+        System.arraycopy(array, 0, result, 0, index);
+        if (index < length - 1) {
+            System.arraycopy(array, index + 1, result, index, length - index - 1);
+        }
+
+        return result;
     }
 
     /**
-     * <p>Checks if an array of primitive floats is empty or {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
+     *
+     * <pre>
+     * ArrayUtils.remove([1], 0)         = []
+     * ArrayUtils.remove([2, 6], 0)      = [6]
+     * ArrayUtils.remove([2, 6], 1)      = [2]
+     * ArrayUtils.remove([2, 6, 3], 1)   = [2, 3]
+     * </pre>
+     *
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
      * @since 2.1
      */
-    public static boolean isEmpty(final float[] array) {
-        return getLength(array) == 0;
+    public static short[] remove(final short[] array, final int index) {
+        return (short[]) remove((Object) array, index);
     }
 
     /**
-     * <p>Checks if an array of primitive booleans is empty or {@code null}.
+     * <p>Removes the element at the specified position from the specified array.
+     * All subsequent elements are shifted to the left (subtracts one from
+     * their indices).
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is empty or {@code null}
+     * <p>This method returns a new array with the same elements of the input
+     * array except the element on the specified position. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
+     *
+     * <pre>
+     * ArrayUtils.remove(["a"], 0)           = []
+     * ArrayUtils.remove(["a", "b"], 0)      = ["b"]
+     * ArrayUtils.remove(["a", "b"], 1)      = ["a"]
+     * ArrayUtils.remove(["a", "b", "c"], 1) = ["a", "c"]
+     * </pre>
+     *
+     * @param <T> the component type of the array
+     * @param array  the array to remove the element from, may not be {@code null}
+     * @param index  the position of the element to be removed
+     * @return A new array containing the existing elements except the element
+     *         at the specified position.
+     * @throws IndexOutOfBoundsException if the index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
      * @since 2.1
      */
-    public static boolean isEmpty(final boolean[] array) {
-        return getLength(array) == 0;
+    @SuppressWarnings("unchecked") // remove() always creates an array of the same type as its input
+    public static <T> T[] remove(final T[] array, final int index) {
+        return (T[]) remove((Object) array, index);
     }
 
-    // ----------------------------------------------------------------------
     /**
-     * <p>Checks if an array of Objects is not empty and not {@code null}.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
      *
-     * @param <T> the component type of the array
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
-     */
-     public static <T> boolean isNotEmpty(final T[] array) {
-         return !isEmpty(array);
-     }
-
-    /**
-     * <p>Checks if an array of primitive longs is not empty and not {@code null}.
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
+     *
+     * <pre>
+     * ArrayUtils.removeAll([true, false, true], 0, 2) = [false]
+     * ArrayUtils.removeAll([true, false, true], 1, 2) = [true]
+     * </pre>
+     *
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
      */
-    public static boolean isNotEmpty(final long[] array) {
-        return !isEmpty(array);
+    public static boolean[] removeAll(final boolean[] array, final int... indices) {
+        return (boolean[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Checks if an array of primitive ints is not empty and not {@code null}.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
+     *
+     * <pre>
+     * ArrayUtils.removeAll([1], 0)             = []
+     * ArrayUtils.removeAll([2, 6], 0)          = [6]
+     * ArrayUtils.removeAll([2, 6], 0, 1)       = []
+     * ArrayUtils.removeAll([2, 6, 3], 1, 2)    = [2]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 2)    = [6]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = []
+     * </pre>
+     *
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
      */
-    public static boolean isNotEmpty(final int[] array) {
-        return !isEmpty(array);
+    public static byte[] removeAll(final byte[] array, final int... indices) {
+        return (byte[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Checks if an array of primitive shorts is not empty and not {@code null}.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
-     */
-    public static boolean isNotEmpty(final short[] array) {
-        return !isEmpty(array);
-    }
-
-    /**
-     * <p>Checks if an array of primitive chars is not empty and not {@code null}.
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
-     */
-    public static boolean isNotEmpty(final char[] array) {
-        return !isEmpty(array);
-    }
-
-    /**
-     * <p>Checks if an array of primitive bytes is not empty and not {@code null}.
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
-     */
-    public static boolean isNotEmpty(final byte[] array) {
-        return !isEmpty(array);
-    }
-
-    /**
-     * <p>Checks if an array of primitive doubles is not empty and not {@code null}.
+     * <pre>
+     * ArrayUtils.removeAll([1], 0)             = []
+     * ArrayUtils.removeAll([2, 6], 0)          = [6]
+     * ArrayUtils.removeAll([2, 6], 0, 1)       = []
+     * ArrayUtils.removeAll([2, 6, 3], 1, 2)    = [2]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 2)    = [6]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = []
+     * </pre>
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
      */
-    public static boolean isNotEmpty(final double[] array) {
-        return !isEmpty(array);
+    public static char[] removeAll(final char[] array, final int... indices) {
+        return (char[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Checks if an array of primitive floats is not empty and not {@code null}.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
-     */
-    public static boolean isNotEmpty(final float[] array) {
-        return !isEmpty(array);
-    }
-
-    /**
-     * <p>Checks if an array of primitive booleans is not empty and not {@code null}.
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array  the array to test
-     * @return {@code true} if the array is not empty and not {@code null}
-     * @since 2.5
-     */
-    public static boolean isNotEmpty(final boolean[] array) {
-        return !isEmpty(array);
-    }
-
-    /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
      * <pre>
-     * ArrayUtils.addAll(null, null)     = null
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
-     * ArrayUtils.addAll([null], [null]) = [null, null]
-     * ArrayUtils.addAll(["a", "b", "c"], ["1", "2", "3"]) = ["a", "b", "c", "1", "2", "3"]
+     * ArrayUtils.removeAll([1], 0)             = []
+     * ArrayUtils.removeAll([2, 6], 0)          = [6]
+     * ArrayUtils.removeAll([2, 6], 0, 1)       = []
+     * ArrayUtils.removeAll([2, 6, 3], 1, 2)    = [2]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 2)    = [6]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = []
      * </pre>
      *
-     * @param <T> the component type of the array
-     * @param array1  the first array whose elements are added to the new array, may be {@code null}
-     * @param array2  the second array whose elements are added to the new array, may be {@code null}
-     * @return The new array, {@code null} if both arrays are {@code null}.
-     *      The type of the new array is the type of the first array,
-     *      unless the first array is null, in which case the type is the same as the second array.
-     * @since 2.1
-     * @throws IllegalArgumentException if the array types are incompatible
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
      */
-    public static <T> T[] addAll(final T[] array1, @SuppressWarnings("unchecked") final T... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
-        }
-        final Class<?> type1 = array1.getClass().getComponentType();
-        @SuppressWarnings("unchecked") // OK, because array is of type T
-        final T[] joinedArray = (T[]) Array.newInstance(type1, array1.length + array2.length);
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        try {
-            System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        } catch (final ArrayStoreException ase) {
-            // Check if problem was due to incompatible types
-            /*
-             * We do this here, rather than before the copy because:
-             * - it would be a wasted check most of the time
-             * - safer, in case check turns out to be too strict
-             */
-            final Class<?> type2 = array2.getClass().getComponentType();
-            if (!type1.isAssignableFrom(type2)) {
-                throw new IllegalArgumentException("Cannot store " + type2.getName() + " in an array of "
-                        + type1.getName(), ase);
-            }
-            throw ase; // No, so rethrow original
-        }
-        return joinedArray;
+    public static double[] removeAll(final double[] array, final int... indices) {
+        return (double[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
+     *
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
      * <pre>
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
+     * ArrayUtils.removeAll([1], 0)             = []
+     * ArrayUtils.removeAll([2, 6], 0)          = [6]
+     * ArrayUtils.removeAll([2, 6], 0, 1)       = []
+     * ArrayUtils.removeAll([2, 6, 3], 1, 2)    = [2]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 2)    = [6]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = []
      * </pre>
      *
-     * @param array1  the first array whose elements are added to the new array.
-     * @param array2  the second array whose elements are added to the new array.
-     * @return The new boolean[] array.
-     * @since 2.1
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
      */
-    public static boolean[] addAll(final boolean[] array1, final boolean... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
-        }
-        final boolean[] joinedArray = new boolean[array1.length + array2.length];
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        return joinedArray;
+    public static float[] removeAll(final float[] array, final int... indices) {
+        return (float[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
+     *
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
      * <pre>
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
+     * ArrayUtils.removeAll([1], 0)             = []
+     * ArrayUtils.removeAll([2, 6], 0)          = [6]
+     * ArrayUtils.removeAll([2, 6], 0, 1)       = []
+     * ArrayUtils.removeAll([2, 6, 3], 1, 2)    = [2]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 2)    = [6]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = []
      * </pre>
      *
-     * @param array1  the first array whose elements are added to the new array.
-     * @param array2  the second array whose elements are added to the new array.
-     * @return The new char[] array.
-     * @since 2.1
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
      */
-    public static char[] addAll(final char[] array1, final char... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
-        }
-        final char[] joinedArray = new char[array1.length + array2.length];
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        return joinedArray;
+    public static int[] removeAll(final int[] array, final int... indices) {
+        return (int[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
      *
-     * <pre>
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
-     * </pre>
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
-     * @param array1  the first array whose elements are added to the new array.
-     * @param array2  the second array whose elements are added to the new array.
-     * @return The new byte[] array.
-     * @since 2.1
-     */
-    public static byte[] addAll(final byte[] array1, final byte... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
-        }
-        final byte[] joinedArray = new byte[array1.length + array2.length];
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        return joinedArray;
-    }
-
-    /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
      * <pre>
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
+     * ArrayUtils.removeAll([1], 0)             = []
+     * ArrayUtils.removeAll([2, 6], 0)          = [6]
+     * ArrayUtils.removeAll([2, 6], 0, 1)       = []
+     * ArrayUtils.removeAll([2, 6, 3], 1, 2)    = [2]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 2)    = [6]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = []
      * </pre>
      *
-     * @param array1  the first array whose elements are added to the new array.
-     * @param array2  the second array whose elements are added to the new array.
-     * @return The new short[] array.
-     * @since 2.1
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
      */
-    public static short[] addAll(final short[] array1, final short... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
-        }
-        final short[] joinedArray = new short[array1.length + array2.length];
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        return joinedArray;
+    public static long[] removeAll(final long[] array, final int... indices) {
+        return (long[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
-     *
-     * <pre>
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
-     * </pre>
+     * Removes multiple array elements specified by indices.
      *
-     * @param array1  the first array whose elements are added to the new array.
-     * @param array2  the second array whose elements are added to the new array.
-     * @return The new int[] array.
-     * @since 2.1
+     * @param array source
+     * @param indices to remove
+     * @return new array of same type minus elements specified by the set bits in {@code indices}
+     * @since 3.2
      */
-    public static int[] addAll(final int[] array1, final int... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
+    // package protected for access by unit tests
+    static Object removeAll(final Object array, final BitSet indices) {
+        if (array == null) {
+            return null;
         }
-        final int[] joinedArray = new int[array1.length + array2.length];
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        return joinedArray;
+
+        final int srcLength = getLength(array);
+        // No need to check maxIndex here, because method only currently called from removeElements()
+        // which guarantee to generate on;y valid bit entries.
+//        final int maxIndex = indices.length();
+//        if (maxIndex > srcLength) {
+//            throw new IndexOutOfBoundsException("Index: " + (maxIndex-1) + ", Length: " + srcLength);
+//        }
+        final int removals = indices.cardinality(); // true bits are items to remove
+        final Object result = Array.newInstance(array.getClass().getComponentType(), srcLength - removals);
+        int srcIndex = 0;
+        int destIndex = 0;
+        int count;
+        int set;
+        while ((set = indices.nextSetBit(srcIndex)) != -1) {
+            count = set - srcIndex;
+            if (count > 0) {
+                System.arraycopy(array, srcIndex, result, destIndex, count);
+                destIndex += count;
+            }
+            srcIndex = indices.nextClearBit(set);
+        }
+        count = srcLength - srcIndex;
+        if (count > 0) {
+            System.arraycopy(array, srcIndex, result, destIndex, count);
+        }
+        return result;
     }
 
     /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
-     *
-     * <pre>
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
-     * </pre>
-     *
-     * @param array1  the first array whose elements are added to the new array.
-     * @param array2  the second array whose elements are added to the new array.
-     * @return The new long[] array.
-     * @since 2.1
+     * Removes multiple array elements specified by index.
+     * @param array source
+     * @param indices to remove
+     * @return new array of same type minus elements specified by unique values of {@code indices}
+     * @since 3.0.1
      */
-    public static long[] addAll(final long[] array1, final long... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
+    // package protected for access by unit tests
+    static Object removeAll(final Object array, final int... indices) {
+        final int length = getLength(array);
+        int diff = 0; // number of distinct indexes, i.e. number of entries that will be removed
+        final int[] clonedIndices = clone(indices);
+        Arrays.sort(clonedIndices);
+
+        // identify length of result array
+        if (isNotEmpty(clonedIndices)) {
+            int i = clonedIndices.length;
+            int prevIndex = length;
+            while (--i >= 0) {
+                final int index = clonedIndices[i];
+                if (index < 0 || index >= length) {
+                    throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + length);
+                }
+                if (index >= prevIndex) {
+                    continue;
+                }
+                diff++;
+                prevIndex = index;
+            }
         }
-        final long[] joinedArray = new long[array1.length + array2.length];
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        return joinedArray;
+
+        // create result array
+        final Object result = Array.newInstance(array.getClass().getComponentType(), length - diff);
+        if (diff < length) {
+            int end = length; // index just after last copy
+            int dest = length - diff; // number of entries so far not copied
+            for (int i = clonedIndices.length - 1; i >= 0; i--) {
+                final int index = clonedIndices[i];
+                if (end - index > 1) { // same as (cp > 0)
+                    final int cp = end - index - 1;
+                    dest -= cp;
+                    System.arraycopy(array, index + 1, result, dest, cp);
+                    // Afer this copy, we still have room for dest items.
+                }
+                end = index;
+            }
+            if (end > 0) {
+                System.arraycopy(array, 0, result, 0, end);
+            }
+        }
+        return result;
     }
 
     /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
+     *
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
      * <pre>
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
+     * ArrayUtils.removeAll([1], 0)             = []
+     * ArrayUtils.removeAll([2, 6], 0)          = [6]
+     * ArrayUtils.removeAll([2, 6], 0, 1)       = []
+     * ArrayUtils.removeAll([2, 6, 3], 1, 2)    = [2]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 2)    = [6]
+     * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = []
      * </pre>
      *
-     * @param array1  the first array whose elements are added to the new array.
-     * @param array2  the second array whose elements are added to the new array.
-     * @return The new float[] array.
-     * @since 2.1
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
      */
-    public static float[] addAll(final float[] array1, final float... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
-        }
-        final float[] joinedArray = new float[array1.length + array2.length];
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        return joinedArray;
+    public static short[] removeAll(final short[] array, final int... indices) {
+        return (short[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Adds all the elements of the given arrays into a new array.
-     * <p>The new array contains all of the element of {@code array1} followed
-     * by all of the elements {@code array2}. When an array is returned, it is always
-     * a new array.
+     * <p>Removes the elements at the specified positions from the specified array.
+     * All remaining elements are shifted to the left.
+     *
+     * <p>This method returns a new array with the same elements of the input
+     * array except those at the specified positions. The component
+     * type of the returned array is always the same as that of the input
+     * array.
+     *
+     * <p>If the input array is {@code null}, an IndexOutOfBoundsException
+     * will be thrown, because in that case no valid index can be specified.
      *
      * <pre>
-     * ArrayUtils.addAll(array1, null)   = cloned copy of array1
-     * ArrayUtils.addAll(null, array2)   = cloned copy of array2
-     * ArrayUtils.addAll([], [])         = []
+     * ArrayUtils.removeAll(["a", "b", "c"], 0, 2) = ["b"]
+     * ArrayUtils.removeAll(["a", "b", "c"], 1, 2) = ["a"]
      * </pre>
      *
-     * @param array1  the first array whose elements are added to the new array.
-     * @param array2  the second array whose elements are added to the new array.
-     * @return The new double[] array.
-     * @since 2.1
-     */
-    public static double[] addAll(final double[] array1, final double... array2) {
-        if (array1 == null) {
-            return clone(array2);
-        } else if (array2 == null) {
-            return clone(array1);
-        }
-        final double[] joinedArray = new double[array1.length + array2.length];
-        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
-        System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
-        return joinedArray;
+     * @param <T> the component type of the array
+     * @param array   the array to remove the element from, may not be {@code null}
+     * @param indices the positions of the elements to be removed
+     * @return A new array containing the existing elements except those
+     *         at the specified positions.
+     * @throws IndexOutOfBoundsException if any index is out of range
+     * (index &lt; 0 || index &gt;= array.length), or if the array is {@code null}.
+     * @since 3.0.1
+     */
+    @SuppressWarnings("unchecked") // removeAll() always creates an array of the same type as its input
+    public static <T> T[] removeAll(final T[] array, final int... indices) {
+        return (T[]) removeAll((Object) array, indices);
     }
 
     /**
-     * <p>Copies the given array and adds the given element at the end of the new array.
-     *
-     * <p>The new array contains the same elements of the input
-     * array plus the given element in the last position. The component type of
-     * the new array is the same as that of the input array.
+     * Removes the occurrences of the specified element from the specified boolean array.
      *
-     * <p>If the input array is {@code null}, a new one element array is returned
-     *  whose component type is the same as the element, unless the element itself is null,
-     *  in which case the return type is Object[]
+     * <p>
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
+     * </p>
      *
-     * <pre>
-     * ArrayUtils.add(null, null)      = IllegalArgumentException
-     * ArrayUtils.add(null, "a")       = ["a"]
-     * ArrayUtils.add(["a"], null)     = ["a", null]
-     * ArrayUtils.add(["a"], "b")      = ["a", "b"]
-     * ArrayUtils.add(["a", "b"], "c") = ["a", "b", "c"]
-     * </pre>
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param <T> the component type of the array
-     * @param array  the array to "add" the element to, may be {@code null}
-     * @param element  the object to add, may be {@code null}
-     * @return A new array containing the existing elements plus the new element
-     * The returned array type will be that of the input array (unless null),
-     * in which case it will have the same type as the element.
-     * If both are null, an IllegalArgumentException is thrown
-     * @since 2.1
-     * @throws IllegalArgumentException if both arguments are null
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static <T> T[] add(final T[] array, final T element) {
-        Class<?> type;
-        if (array != null) {
-            type = array.getClass().getComponentType();
-        } else if (element != null) {
-            type = element.getClass();
-        } else {
-            throw new IllegalArgumentException("Arguments cannot both be null");
-        }
-        @SuppressWarnings("unchecked") // type must be T
-        final
-        T[] newArray = (T[]) copyArrayGrow1(array, type);
-        newArray[newArray.length - 1] = element;
-        return newArray;
+    public static boolean[] removeAllOccurences(final boolean[] array, final boolean element) {
+        return (boolean[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
-     *
-     * <p>
-     * The new array contains the same elements of the input array plus the given element in the first position. The
-     * component type of the new array is the same as that of the input array.
-     * </p>
+     * Removes the occurrences of the specified element from the specified byte array.
      *
      * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element.
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
      * </p>
      *
-     * <pre>
-     * ArrayUtils.add(null, true)          = [true]
-     * ArrayUtils.add([true], false)       = [false, true]
-     * ArrayUtils.add([true, false], true) = [true, true, false]
-     * </pre>
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param array the array to "add" the element to, may be {@code null}.
-     * @param element the object to add.
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element.
-     * @since 3.10
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static boolean[] addFirst(final boolean[] array, final boolean element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static byte[] removeAllOccurences(final byte[] array, final byte element) {
+        return (byte[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
-     *
-     * <p>
-     * The new array contains the same elements of the input array plus the given element in the first position. The
-     * component type of the new array is the same as that of the input array.
-     * </p>
+     * Removes the occurrences of the specified element from the specified char array.
      *
      * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element.
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
      * </p>
      *
-     * <pre>
-     * ArrayUtils.add(null, 1)   = [1]
-     * ArrayUtils.add([1], 0)    = [0, 1]
-     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
-     * </pre>
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param array the array to "add" the element to, may be {@code null}.
-     * @param element the object to add.
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element.
-     * @since 3.10
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static byte[] addFirst(final byte[] array, final byte element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static char[] removeAllOccurences(final char[] array, final char element) {
+        return (char[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
-     *
-     * <p>
-     * The new array contains the same elements of the input array plus the given element in the first position. The
-     * component type of the new array is the same as that of the input array.
-     * </p>
+     * Removes the occurrences of the specified element from the specified double array.
      *
      * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element.
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
      * </p>
      *
-     * <pre>
-     * ArrayUtils.add(null, '1')       = ['1']
-     * ArrayUtils.add(['1'], '0')      = ['0', '1']
-     * ArrayUtils.add(['1', '0'], '1') = ['1', '1', '0']
-     * </pre>
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param array the array to "add" the element to, may be {@code null}.
-     * @param element the object to add.
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element.
-     * @since 3.10
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static char[] addFirst(final char[] array, final char element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static double[] removeAllOccurences(final double[] array, final double element) {
+        return (double[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
-     *
-     * <p>
-     * The new array contains the same elements of the input array plus the given element in the first position. The
-     * component type of the new array is the same as that of the input array.
-     * </p>
+     * Removes the occurrences of the specified element from the specified float array.
      *
      * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element.
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
      * </p>
      *
-     * <pre>
-     * ArrayUtils.add(null, 1)   = [1]
-     * ArrayUtils.add([1], 0)    = [0, 1]
-     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
-     * </pre>
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param array the array to "add" the element to, may be {@code null}.
-     * @param element the object to add.
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element.
-     * @since 3.10
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static double[] addFirst(final double[] array, final double element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static float[] removeAllOccurences(final float[] array, final float element) {
+        return (float[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
-     *
-     * <p>
-     * The new array contains the same elements of the input array plus the given element in the first position. The
-     * component type of the new array is the same as that of the input array.
-     * </p>
+     * Removes the occurrences of the specified element from the specified int array.
      *
      * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element.
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
      * </p>
      *
-     * <pre>
-     * ArrayUtils.add(null, 1)   = [1]
-     * ArrayUtils.add([1], 0)    = [0, 1]
-     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
-     * </pre>
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param array the array to "add" the element to, may be {@code null}.
-     * @param element the object to add.
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element.
-     * @since 3.10
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static float[] addFirst(final float[] array, final float element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static int[] removeAllOccurences(final int[] array, final int element) {
+        return (int[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
-     *
-     * <p>
-     * The new array contains the same elements of the input array plus the given element in the first position. The
-     * component type of the new array is the same as that of the input array.
-     * </p>
+     * Removes the occurrences of the specified element from the specified long array.
      *
      * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element.
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
      * </p>
      *
-     * <pre>
-     * ArrayUtils.add(null, 1)   = [1]
-     * ArrayUtils.add([1], 0)    = [0, 1]
-     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
-     * </pre>
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param array the array to "add" the element to, may be {@code null}.
-     * @param element the object to add.
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element.
-     * @since 3.10
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static int[] addFirst(final int[] array, final int element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static long[] removeAllOccurences(final long[] array, final long element) {
+        return (long[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
+     * Removes the occurrences of the specified element from the specified short array.
      *
      * <p>
-     * The new array contains the same elements of the input array plus the given element in the first position. The
-     * component type of the new array is the same as that of the input array.
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
      * </p>
      *
-     * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element.
-     * </p>
-     *
-     * <pre>
-     * ArrayUtils.add(null, 1)   = [1]
-     * ArrayUtils.add([1], 0)    = [0, 1]
-     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
-     * </pre>
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param array the array to "add" the element to, may be {@code null}.
-     * @param element the object to add.
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element.
-     * @since 3.10
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static long[] addFirst(final long[] array, final long element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static short[] removeAllOccurences(final short[] array, final short element) {
+        return (short[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
-     *
-     * <p>
-     * The new array contains the same elements of the input array plus the given element in the first position. The
-     * component type of the new array is the same as that of the input array.
-     * </p>
+     * Removes the occurrences of the specified element from the specified array.
      *
      * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element.
+     * All subsequent elements are shifted to the left (subtracts one from their indices).
+     * If the array doesn't contains such an element, no elements are removed from the array.
+     * <code>null</code> will be returned if the input array is <code>null</code>.
      * </p>
      *
-     * <pre>
-     * ArrayUtils.add(null, 1)   = [1]
-     * ArrayUtils.add([1], 0)    = [0, 1]
-     * ArrayUtils.add([1, 0], 1) = [1, 1, 0]
-     * </pre>
+     * @param <T> the type of object in the array
+     * @param element the element to remove
+     * @param array the input array
      *
-     * @param array the array to "add" the element to, may be {@code null}.
-     * @param element the object to add.
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element.
-     * @since 3.10
+     * @return A new array containing the existing elements except the occurrences of the specified element.
+     * @since 3.5
      */
-    public static short[] addFirst(final short[] array, final short element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static <T> T[] removeAllOccurences(final T[] array, final T element) {
+        return (T[]) removeAll((Object) array, indexesOf(array, element));
     }
 
     /**
-     * Copies the given array and adds the given element at the beginning of the new array.
-     *
-     * <p>
-     * The new array contains the same elements of the input array plus the given element in the first positioaddFirstaddFirstaddFirstn. The
-     * component type of the new array is the same as that of the input array.
-     * </p>
+     * <p>Removes the first occurrence of the specified element from the
+     * specified array. All subsequent elements are shifted to the left
+     * (subtracts one from their indices). If the array doesn't contains
+     * such an element, no elements are removed from the array.
      *
-     * <p>
-     * If the input array is {@code null}, a new one element array is returned whose component type is the same as the
-     * element, unless the element itself is null, in which case the return type is Object[]
-     * </p>
+     * <p>This method returns a new array with the same elements of the input
+     * array except the first occurrence of the specified element. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
      * <pre>
-     * ArrayUtils.add(null, null)      = IllegalArgumentException
-     * ArrayUtils.add(null, "a")       = ["a"]
-     * ArrayUtils.add(["a"], null)     = [null, "a"]
-     * ArrayUtils.add(["a"], "b")      = ["b", "a"]
-     * ArrayUtils.add(["a", "b"], "c") = ["c", "a", "b"]
+     * ArrayUtils.removeElement(null, true)                = null
+     * ArrayUtils.removeElement([], true)                  = []
+     * ArrayUtils.removeElement([true], false)             = [true]
+     * ArrayUtils.removeElement([true, false], false)      = [true]
+     * ArrayUtils.removeElement([true, false, true], true) = [false, true]
      * </pre>
      *
-     * @param <T> the component type of the array
-     * @param array the array to "add" the element to, may be {@code null}
-     * @param element the object to add, may be {@code null}
-     * @return A new array containing the existing elements plus the new element The returned array type will be that of
-     *         the input array (unless null), in which case it will have the same type as the element. If both are null,
-     *         an IllegalArgumentException is thrown
-     * @since 3.10
-     * @throws IllegalArgumentException if both arguments are null
+     * @param array  the array to remove the element from, may be {@code null}
+     * @param element  the element to be removed
+     * @return A new array containing the existing elements except the first
+     *         occurrence of the specified element.
+     * @since 2.1
      */
-    public static <T> T[] addFirst(final T[] array, final T element) {
-        return array == null ? add(array, element) : insert(0, array, element);
+    public static boolean[] removeElement(final boolean[] array, final boolean element) {
+        final int index = indexOf(array, element);
+        if (index == INDEX_NOT_FOUND) {
+            return clone(array);
+        }
+        return remove(array, index);
     }
 
     /**
-     * <p>Copies the given array and adds the given element at the end of the new array.
-     *
-     * <p>The new array contains the same elements of the input
-     * array plus the given element in the last position. The component type of
-     * the new array is the same as that of the input array.
+     * <p>Removes the first occurrence of the specified element from the
+     * specified array. All subsequent elements are shifted to the left
+     * (subtracts one from their indices). If the array doesn't contains
+     * such an element, no elements are removed from the array.
      *
-     * <p>If the input array is {@code null}, a new one element array is returned
-     *  whose component type is the same as the element.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the first occurrence of the specified element. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
      * <pre>
-     * ArrayUtils.add(null, true)          = [true]
-     * ArrayUtils.add([true], false)       = [true, false]
-     * ArrayUtils.add([true, false], true) = [true, false, true]
+     * ArrayUtils.removeElement(null, 1)        = null
+     * ArrayUtils.removeElement([], 1)          = []
+     * ArrayUtils.removeElement([1], 0)         = [1]
+     * ArrayUtils.removeElement([1, 0], 0)      = [1]
+     * ArrayUtils.removeElement([1, 0, 1], 1)   = [0, 1]
      * </pre>
      *
-     * @param array  the array to copy and add the element to, may be {@code null}
-     * @param element  the object to add at the last index of the new array
-     * @return A new array containing the existing elements plus the new element
+     * @param array  the array to remove the element from, may be {@code null}
+     * @param element  the element to be removed
+     * @return A new array containing the existing elements except the first
+     *         occurrence of the specified element.
      * @since 2.1
      */
-    public static boolean[] add(final boolean[] array, final boolean element) {
-        final boolean[] newArray = (boolean[]) copyArrayGrow1(array, Boolean.TYPE);
-        newArray[newArray.length - 1] = element;
-        return newArray;
+    public static byte[] removeElement(final byte[] array, final byte element) {
+        final int index = indexOf(array, element);
+        if (index == INDEX_NOT_FOUND) {
+            return clone(array);
+        }
+        return remove(array, index);
     }
 
     /**
-     * <p>Copies the given array and adds the given element at the end of the new array.
-     *
-     * <p>The new array contains the same elements of the input
-     * array plus the given element in the last position. The component type of
-     * the new array is the same as that of the input array.
+     * <p>Removes the first occurrence of the specified element from the
+     * specified array. All subsequent elements are shifted to the left
+     * (subtracts one from their indices). If the array doesn't contains
+     * such an element, no elements are removed from the array.
      *
-     * <p>If the input array is {@code null}, a new one element array is returned
-     *  whose component type is the same as the element.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the first occurrence of the specified element. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
      * <pre>
-     * ArrayUtils.add(null, 0)   = [0]
-     * ArrayUtils.add([1], 0)    = [1, 0]
-     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * ArrayUtils.removeElement(null, 'a')            = null
+     * ArrayUtils.removeElement([], 'a')              = []
+     * ArrayUtils.removeElement(['a'], 'b')           = ['a']
+     * ArrayUtils.removeElement(['a', 'b'], 'a')      = ['b']
+     * ArrayUtils.removeElement(['a', 'b', 'a'], 'a') = ['b', 'a']
      * </pre>
      *
-     * @param array  the array to copy and add the element to, may be {@code null}
-     * @param element  the object to add at the last index of the new array
-     * @return A new array containing the existing elements plus the new element
+     * @param array  the array to remove the element from, may be {@code null}
+     * @param element  the element to be removed
+     * @return A new array containing the existing elements except the first
+     *         occurrence of the specified element.
      * @since 2.1
      */
-    public static byte[] add(final byte[] array, final byte element) {
-        final byte[] newArray = (byte[]) copyArrayGrow1(array, Byte.TYPE);
-        newArray[newArray.length - 1] = element;
-        return newArray;
+    public static char[] removeElement(final char[] array, final char element) {
+        final int index = indexOf(array, element);
+        if (index == INDEX_NOT_FOUND) {
+            return clone(array);
+        }
+        return remove(array, index);
     }
 
     /**
-     * <p>Copies the given array and adds the given element at the end of the new array.
-     *
-     * <p>The new array contains the same elements of the input
-     * array plus the given element in the last position. The component type of
-     * the new array is the same as that of the input array.
+     * <p>Removes the first occurrence of the specified element from the
+     * specified array. All subsequent elements are shifted to the left
+     * (subtracts one from their indices). If the array doesn't contains
+     * such an element, no elements are removed from the array.
      *
-     * <p>If the input array is {@code null}, a new one element array is returned
-     *  whose component type is the same as the element.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the first occurrence of the specified element. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
      * <pre>
-     * ArrayUtils.add(null, '0')       = ['0']
-     * ArrayUtils.add(['1'], '0')      = ['1', '0']
-     * ArrayUtils.add(['1', '0'], '1') = ['1', '0', '1']
+     * ArrayUtils.removeElement(null, 1.1)            = null
+     * ArrayUtils.removeElement([], 1.1)              = []
+     * ArrayUtils.removeElement([1.1], 1.2)           = [1.1]
+     * ArrayUtils.removeElement([1.1, 2.3], 1.1)      = [2.3]
+     * ArrayUtils.removeElement([1.1, 2.3, 1.1], 1.1) = [2.3, 1.1]
      * </pre>
      *
-     * @param array  the array to copy and add the element to, may be {@code null}
-     * @param element  the object to add at the last index of the new array
-     * @return A new array containing the existing elements plus the new element
+     * @param array  the array to remove the element from, may be {@code null}
+     * @param element  the element to be removed
+     * @return A new array containing the existing elements except the first
+     *         occurrence of the specified element.
      * @since 2.1
      */
-    public static char[] add(final char[] array, final char element) {
-        final char[] newArray = (char[]) copyArrayGrow1(array, Character.TYPE);
-        newArray[newArray.length - 1] = element;
-        return newArray;
+    public static double[] removeElement(final double[] array, final double element) {
+        final int index = indexOf(array, element);
+        if (index == INDEX_NOT_FOUND) {
+            return clone(array);
+        }
+        return remove(array, index);
     }
 
     /**
-     * <p>Copies the given array and adds the given element at the end of the new array.
-     *
-     * <p>The new array contains the same elements of the input
-     * array plus the given element in the last position. The component type of
-     * the new array is the same as that of the input array.
+     * <p>Removes the first occurrence of the specified element from the
+     * specified array. All subsequent elements are shifted to the left
+     * (subtracts one from their indices). If the array doesn't contains
+     * such an element, no elements are removed from the array.
      *
-     * <p>If the input array is {@code null}, a new one element array is returned
-     *  whose component type is the same as the element.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the first occurrence of the specified element. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
      * <pre>
-     * ArrayUtils.add(null, 0)   = [0]
-     * ArrayUtils.add([1], 0)    = [1, 0]
-     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * ArrayUtils.removeElement(null, 1.1)            = null
+     * ArrayUtils.removeElement([], 1.1)              = []
+     * ArrayUtils.removeElement([1.1], 1.2)           = [1.1]
+     * ArrayUtils.removeElement([1.1, 2.3], 1.1)      = [2.3]
+     * ArrayUtils.removeElement([1.1, 2.3, 1.1], 1.1) = [2.3, 1.1]
      * </pre>
      *
-     * @param array  the array to copy and add the element to, may be {@code null}
-     * @param element  the object to add at the last index of the new array
-     * @return A new array containing the existing elements plus the new element
+     * @param array  the array to remove the element from, may be {@code null}
+     * @param element  the element to be removed
+     * @return A new array containing the existing elements except the first
+     *         occurrence of the specified element.
      * @since 2.1
      */
-    public static double[] add(final double[] array, final double element) {
-        final double[] newArray = (double[]) copyArrayGrow1(array, Double.TYPE);
-        newArray[newArray.length - 1] = element;
-        return newArray;
-    }
-
-    /**
-     * <p>Copies the given array and adds the given element at the end of the new array.
-     *
-     * <p>The new array contains the same elements of the input
-     * array plus the given element in the last position. The component type of
-     * the new array is the same as that of the input array.
-     *
-     * <p>If the input array is {@code null}, a new one element array is returned
-     *  whose component type is the same as the element.
-     *
-     * <pre>
-     * ArrayUtils.add(null, 0)   = [0]
-     * ArrayUtils.add([1], 0)    = [1, 0]
-     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
-     * </pre>
-     *
-     * @param array  the array to copy and add the element to, may be {@code null}
-     * @param element  the object to add at the last index of the new array
-     * @return A new array containing the existing elements plus the new element
-     * @since 2.1
-     */
-    public static float[] add(final float[] array, final float element) {
-        final float[] newArray = (float[]) copyArrayGrow1(array, Float.TYPE);
-        newArray[newArray.length - 1] = element;
-        return newArray;
+    public static float[] removeElement(final float[] array, final float element) {
+        final int index = indexOf(array, element);
+        if (index == INDEX_NOT_FOUND) {
+            return clone(array);
+        }
+        return remove(array, index);
     }
 
     /**
-     * <p>Copies the given array and adds the given element at the end of the new array.
-     *
-     * <p>The new array contains the same elements of the input
-     * array plus the given element in the last position. The component type of
-     * the new array is the same as that of the input array.
+     * <p>Removes the first occurrence of the specified element from the
+     * specified array. All subsequent elements are shifted to the left
+     * (subtracts one from their indices). If the array doesn't contains
+     * such an element, no elements are removed from the array.
      *
-     * <p>If the input array is {@code null}, a new one element array is returned
-     *  whose component type is the same as the element.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the first occurrence of the specified element. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
      * <pre>
-     * ArrayUtils.add(null, 0)   = [0]
-     * ArrayUtils.add([1], 0)    = [1, 0]
-     * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
+     * ArrayUtils.removeElement(null, 1)      = null
+     * ArrayUtils.removeElement([], 1)        = []
+     * ArrayUtils.removeElement([1], 2)       = [1]
+     * ArrayUtils.removeElement([1, 3], 1)    = [3]
+     * ArrayUtils.removeElement([1, 3, 1], 1) = [3, 1]
      * </pre>
      *
-     * @param array  the array to copy and add the element to, may be {@code null}
-     * @param element  the object to add at the last index of the new array
-     * @return A new array containing the existing elements plus the new element
+     * @param array  the array to remove the element from, may be {@code null}
+     * @param element  the element to be removed
+     * @return A new array containing the existing elements except the first
+     *         occurrence of the specified element.
      * @since 2.1
      */
-    public static int[] add(final int[] array, final int element) {
-        final int[] newArray = (int[]) copyArrayGrow1(array, Integer.TYPE);
-        newArray[newArray.length - 1] = element;
-        return newArray;
+    public static int[] removeElement(final int[] array, final int element) {
+        final int index = indexOf(array, element);
+        if (index == INDEX_NOT_FOUND) {
+            return clone(array);
+        }
+        return remove(array, index);
     }
 
     /**
-     * <p>Copies the given array and adds the given element at the end of the new array.
-     *
-     * <p>The new array contains the same elements of the input
-     * array plus the given element in the last position. The component type of
-     * the new array is the same as that of the input array.
+     * <p>Removes the first occurrence of the specified element from the
+     * specified array. All subsequent elements are shifted to the left
+     * (subtracts one from their indices). If the array doesn't contains
+     * such an element, no elements are removed from the array.
      *
-     * <p>If the input array is {@code null}, a new one element array is returned
-     *  whose component type is the same as the element.
+     * <p>This method returns a new array with the same elements of the input
+     * array except the first occurrence of the specified element. The component
+     * type of the returned array is always the same as that of the input
+     * array.
      *
      * <pre>
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