Java Array Index Of indexOf(Object[] array, Object objectToFind)

Description

Finds the index of the given object in the array.

This method returns #INDEX_NOT_FOUND (-1) for a null input array.

License

Apache License

Parameter

Parameter	Description
array	the array to search through for the object, may be <code>null</code>
objectToFind	the object to find, may be <code>null</code>

Return

the index of the object within the array, (-1) if not found or null array input

Declaration

public static int indexOf(Object[] array, Object objectToFind)

Method Source Code

//package com.java2s;
/*/*  ww w  .java 2 s . c  o  m*/
 * Copyright 2010 JBoss Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

public class Main {
    public static final int INDEX_NOT_FOUND = -1;

    /**
     * <p>Finds the index of the given object in the array.</p>
     *
     * <p>This method returns {@link #INDEX_NOT_FOUND} (<code>-1</code>) for a <code>null</code> input array.</p>
     * 
     * @param array  the array to search through for the object, may be <code>null</code>
     * @param objectToFind  the object to find, may be <code>null</code>
     * @return the index of the object within the array, 
     *  {@link #INDEX_NOT_FOUND} (<code>-1</code>) if not found or <code>null</code> array input
     */
    public static int indexOf(Object[] array, Object objectToFind) {
        return indexOf(array, objectToFind, 0);
    }

    /**
     * <p>Finds the index of the given object in the array starting at the given index.</p>
     *
     * <p>This method returns {@link #INDEX_NOT_FOUND} (<code>-1</code>) for a <code>null</code> input array.</p>
     *
     * <p>A negative startIndex is treated as zero. A startIndex larger than the array
     * length will return {@link #INDEX_NOT_FOUND} (<code>-1</code>).</p>
     * 
     * @param array  the array to search through for the object, may be <code>null</code>
     * @param objectToFind  the object to find, may be <code>null</code>
     * @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</code>) if not found or <code>null</code> array input
     */
    public static int indexOf(Object[] array, Object objectToFind, int startIndex) {
        if (array == null) {
            return INDEX_NOT_FOUND;
        }
        if (startIndex < 0) {
            startIndex = 0;
        }
        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;
    }

    public static boolean equals(long[] a, long[] a2) {
        return java.util.Arrays.equals(a, a2);
    }

    public static boolean equals(int[] a, int[] a2) {
        return java.util.Arrays.equals(a, a2);
    }

    public static boolean equals(short[] a, short a2[]) {
        return java.util.Arrays.equals(a, a2);
    }

    public static boolean equals(char[] a, char[] a2) {
        return java.util.Arrays.equals(a, a2);
    }

    public static boolean equals(byte[] a, byte[] a2) {
        return java.util.Arrays.equals(a, a2);
    }

    public static boolean equals(boolean[] a, boolean[] a2) {
        return java.util.Arrays.equals(a, a2);
    }

    public static boolean equals(double[] a, double[] a2) {
        return java.util.Arrays.equals(a, a2);
    }

    public static boolean equals(float[] a, float[] a2) {
        return java.util.Arrays.equals(a, a2);
    }

    public static boolean equals(Object[] a, Object[] a2) {
        return java.util.Arrays.equals(a, a2);
    }
}