Java Hash Code Calculate hashCodeOrNull(Object[] array)

Description

Returns a hash code for the elements of the given array, or 0 if it is null.

License

Open Source License

Parameter

Parameter	Description
array	the array.

Return

a hash code.

Declaration

public static int hashCodeOrNull(Object[] array) 

Method Source Code

//package com.java2s;
/*/*from w  w w  . ja v a2 s  .c o  m*/
 * ProGuard -- shrinking, optimization, obfuscation, and preverification
 *             of Java bytecode.
 *
 * Copyright (c) 2002-2016 Eric Lafortune @ GuardSquare
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

public class Main {
    /**
     * Returns a hash code for the elements of the given array, or 0 if it is
     * null.
     * @param array the array.
     * @return a hash code.
     */
    public static int hashCodeOrNull(Object[] array) {
        return array == null ? 0 : hashCode(array, array.length);
    }

    /**
     * Returns a hash code for the elements of the given array, or 0 if it is
     * null.
     * @param array the array.
     * @param size  the size of the array to be taken into account.
     * @return a hash code.
     */
    public static int hashCodeOrNull(Object[] array, int size) {
        return array == null ? 0 : hashCode(array, size);
    }

    /**
     * Returns a hash code for the elements of the given array.
     * @param array the array.
     * @param size  the size of the array to be taken into account.
     * @return a hash code.
     */
    public static int hashCode(byte[] array, int size) {
        int hashCode = 0;

        for (int index = 0; index < size; index++) {
            hashCode ^= array[index];
        }

        return hashCode;
    }

    /**
     * Returns a hash code for the elements of the given array.
     * @param array the array.
     * @param size  the size of the array to be taken into account.
     * @return a hash code.
     */
    public static int hashCode(short[] array, int size) {
        int hashCode = 0;

        for (int index = 0; index < size; index++) {
            hashCode ^= array[index];
        }

        return hashCode;
    }

    /**
     * Returns a hash code for the elements of the given array.
     * @param array the array.
     * @param size  the size of the array to be taken into account.
     * @return a hash code.
     */
    public static int hashCode(int[] array, int size) {
        int hashCode = 0;

        for (int index = 0; index < size; index++) {
            hashCode ^= array[index];
        }

        return hashCode;
    }

    /**
     * Returns a hash code for the elements of the given array.
     * @param array the array.
     * @param size  the size of the array to be taken into account.
     * @return a hash code.
     */
    public static int hashCode(Object[] array, int size) {
        int hashCode = 0;

        for (int index = 0; index < size; index++) {
            hashCode ^= array[index].hashCode();
        }

        return hashCode;
    }
}

Related

1. hashCodeForDoubleArray(double[] a)
2. hashCodeLowerCase(Object... toHash)
3. hashCodeNullSafe(final Object o)
4. hashCodeOf(Object o)
5. hashCodeOrDefault(Object obj)
6. hashCodeOrZero(Object o)
7. hashCodeSafe(final Object value)