Nodejs Utililty Methods Array Filter

Array.prototype.filter = function(f) {
  var filter = [];
  for (var i = 0; i < this.length; i++) {
    if (f(this[i]))
      filter.push(this[i]);
  return filter;
};

Array.prototype.filter = function(filterFunc) {
  var ret = [];
  for(var i = 0; i < this.length; i++) {
    if(filterFunc(this[i])) {
      ret.push(this[i]);
  return ret;
};
...

Array.prototype.filter = function(fn){
    var self = this;
    var arr = [];
    for(var i=0; i<self.length; i++){
        if (fn(self[i])){
            arr.push(self[i]);
    return arr;
...

Array.prototype.filter = function(fn)
    r = [];
    this.forEach(function (item) { if (fn(item)) r.push(item); });
    return r;

Array.prototype.filter = function(fn, context) {
  if (typeof fn != "function") {
    throw new TypeError(fn + " is not a function");
  if (typeof context === 'undefined') {
    context = this;
  var res = [];
  for (var i = 0, l = this.length; i < l; ++i) {
...

"use strict";
Array.isArray = function(arg) {
    return Object.prototype.toString.call(arg) === '[object Array]';
};
Array.prototype.filter = function(fun ) {
    if (this === void 0 || this === null)
        throw new TypeError();
    var t = Object(this);
    var len = t.length >>> 0;
...

Array.prototype.filter = Array.prototype.filter || function(fun ) {
  "use strict";
  if (this === void 0 || this === null) throw new TypeError();
  var t = Object(this);
  var len = t.length >>> 0;
  if (typeof fun !== "function") throw new TypeError();
  var res = [];
  var thisp = arguments[1];
  for (var i = 0; i < len; i++) {
...

Array.prototype.filter = Array.prototype.filter || function(fun ) {
    var len = this.length >>> 0;
    if (typeof fun != "function") {
        throw new TypeError();
    var res = new Array();
    var thisp = arguments[1];
    for (var i = 0; i < len; i++) {
        if (i in this) {
...

"use strict";
Array.prototype.filter = function (fun) {
    let filtered = [];
    for (let i = 0; i < this.length; i++) {
        if (fun(this[i])) {
            filtered.push(this[i]);
    return filtered;
...

"use strict";
Array.prototype.filter = function (fun) {
    let arr = [];
    let thisArg = arguments.length >= 2 ? arguments[1] : void 0;
    for (let i = 0; i < this.length; i++) {
        if (fun.call(thisArg, this[i], i, this)) {
            arr.push(this[i]);
    return arr;