Nodejs Utililty Methods Array Union

Array.prototype.union = function(a) {
    return this.concat(a.remove(this));

Array.union = function(a, b){
     return a.concat(b).uniquelize();
};

Array.prototype.union = function (arr) {
  return this.concat(arr).distinct();
};

Array.prototype.union = function (ary) {
    return this.concat(ary).distinct();
};

Array.prototype.union = function(b) {
  return this.concat(b).uniquelize();
};

Array.prototype.union = function (other) {
  var hash = {};
  for (var i = 0; i < this.length; i++) {
    hash[this[i]] = true;
  for (var j = 0; j < other.length; j++) {
    hash[other[j]] = true;
  return Object.keys(hash);
...

Array.prototype.union = function(t)
    return this.concat(t).unique();

Array.prototype.getUnionAttrStr=function(filed,split){
  try{
  var unionStr=new String();
  if(!split){
    split=",";
  for(var i=0;i<this.length;i++){
    var tempVal=this[i][filed];
    unionStr+=tempVal+split;
...

Array.prototype.getUnionAttrStr=function(filed,split){
  try{
  var unionStr=new String();
  if(!split){
    split=Toyz4js["cfg"]["array_separator"];
  for(var i=0;i<this.length;i++){
    var tempVal=this[i][filed];
    unionStr+=tempVal+split;
...

Array.prototype.getUnionStr=function(filed,split){
  try{
  var unionStr=new String();
  if(!split){
    split=",";
  for(var i=0;i<this.length;i++){
    var tempVal=this[i][filed];
    unionStr+=tempVal+split;
...