Nodejs Utililty Methods Array Append Item

Array.prototype.appendUniqueObj = function(oneItem)
  if (!this.contains(oneItem))
    this[this.length] = oneItem;

Array.prototype.append_all=function(from) {
  for(var i=0;i<from.length;i++) {
    this.append(from[i]);
  return this;

Array.prototype.Append = function( arr )
    for ( var i = 0; i < arr.length; i++ )
        this.push( arr[ i ] );
};

Array.prototype.AddItem = function( item )
  var i = this.length ;
  this[ i ] = item ;
  return i ;

Array.prototype.add = function(a2) {
  var l1 = this.length;
  var l2 = a2.length;
  var len = (l1 < l2 ? l1 : l2);
  var result = new Array(len);
  for (var i = 0; i < len; i++) {
    result[i] = this[i] + a2[i];
  return result;
...

Array.prototype.add = function (e) {
    this.push(e);
};

Array.prototype.add = function(el) {
  this.push(el);
  return this;
};

Array.prototype.add = function (el) {
    var index = this.indexOf(el);
    if (index == -1) {
        this.push(el);
};
Array.prototype.remove = function (el) {
    var index = this.indexOf(el);
    if (index > -1) {
...

Array.prototype.add = function(element) {
  var newSize = this.push(element);
  return newSize-1;

Array.prototype.add = function(elemento,duplicado) {
  if(duplicado===false){
    for (var i = 0; i < this.length; i++) {
      if(this[i]===elemento)
        return;
  this[this.length] = elemento;