Nodejs Array Has Duplicate hasDuplicates()

Method Source Code

/**// w w w. j  a  va2  s .co  m
 * Unit tests:
 * test/js/ArrayTest.js
 */

/**
 * Search for duplicate value.
 * - Shallow search
 * - Compares primitives only
 *
 * return - True if this array has duplicated values.
 */
Array.prototype.hasDuplicates = function() {
    for (var i = 0; i < this.length; i++) {

        var currentVal = this[i];
        for (var j = 0; j < this.length; j++) {

            if(i === j) continue; /* Same object, ignore it. */

            var val = this[j];
            if (currentVal === val) {
                return true;
            }
        }
    }
    return false;
}

Related

1. hasDuplicates()

   Array.prototype.hasDuplicates = function() {
       this.sort();
       for (var i = 1; i < this.length; i++) {
           if (this[i - 1] == this[i]) {
               return true;
       return false;
   };
   ...
   

2. isDuplicate(val)

   Array.prototype.isDuplicate = function(val) {
       for (var i = 0; i < this.length; i++) {
           var currentVal = this[i];
           if (currentVal === val) {
               return true;
       return false;