Java Hash Code Calculate hashCode(Object a)

Description

Get the hashCode of an object.

License

Open Source License

Return

an optimized version of a == null ? 0 : a.hashCode().

Declaration

public static final int hashCode(Object a) 

Method Source Code

//package com.java2s;

public class Main {
    /**//from  w ww  .j  a v a2  s  .  c om
     * Get the hashCode of an object.
     * <p>
     * This method is just a shortcut to simplify assertion statements.</p>
     * @return an optimized version of a <span class="operator">==</span> <span class="keyword">null</span> <span class="operator">?</span> 0 <span class="operator">:</span> a.hashCode().
     * @see #equals(Object, Object)
     */
    public static final int hashCode(Object a) {
        try {
            return a.hashCode();
        } catch (NullPointerException ex) {
            //@internal possibly quicker variant to explicit prechecks for null: simply let this exceptional case occur, and then handle it.
            if (a == null) {
                return 0;
            } else {
                // another cause for the NullPointerException than null arguments
                throw ex;
            }
        }
    }
}

Related

1. hashCode(long a[])
2. hashCode(long longVal)
3. hashCode(long value)
4. hashCode(long x)
5. hashCode(long[] a, int fromIndex, int toIndex)
6. hashCode(Object array)
7. hashCode(Object o)
8. hashCode(Object o)
9. hashCode(Object o)