Javascript Array without(ar)

Array.prototype.without = function(ar) {
 var results = [];
 for (var i = 0, len = this.length; i < len; i++) {
  var found = false;
  for (var j = 0, len2 = ar.length; j < len2; j++) {
   if (this[i] === ar[j]) {
    found = true;//from w  ww  .ja  v a  2 s.  com
    break;
   }
  }
  if (!found) {
   results.push(this[i]);
  }
 }
 
 return results;
};

// refactored
Array.prototype.without = function(ar) {
 var results = [];
 for (var i = 0, len = this.length; i < len; i++) {
  if (ar.indexOf(this[i]) < 0) {
   results.push(this[i]);
  }
 }
 
 return results;
};

// refactored (requires Enumerable)
Array.prototype.without = function() {
 var args = $A(arguments);
 return this.select(function(value) {
  return !args.include(value);
 });
};