Nodejs Utililty Methods Array Map

Array.prototype.map = function(callback) {
  var result = [];
  this.forEach(function(item) {
    result.push(callback(item));
  });
  return result;
};
Array.prototype.concatAll = function(array) {
  var results = [];
...

Array.prototype.map = function(callback) {
  var returnArray=[];
  for (var i=0; i<this.length; i++) {
    returnArray.push(callback(this[i]));
  return returnArray;
};

Array.prototype.map = function(callback, thisArg){
  var newArr = [];
  if(callback && Object.prototype.toString.call(callback) != "[object Function]"){
    throw new TypeError('callback is not a function');
  for(var i = 0, len = this.length; i < len; i++){
    newArr[i] = callback.call(thisArg, this[i], i , this);
  };
  return newArr;
...

Array.prototype.map = Array.prototype.map || (function(callback, thisArg) {
  var T, A, k;
  var O = Object(this);
  var len = O.length >>> 0;
  if (arguments.length > 1) T = thisArg;
  A = new Array(len);
  k = 0;
  while (k < len) {
    var kValue, mappedValue;
...

Array.prototype.map = function (callbackfn, thisArg) {
  var res = [];
  for (var i=0; i<this.length; i++)
    res[i] = Kernel.Reflect.apply(callbackfn, thisArg, [this[i], i, this]);
  return res;

Array.prototype.map = function(cb){
    var arr = Object(this);
    var res = []
    for(var i=0;i<arr.length;i++){
        res[i] = cb.call(arr[i], i);
    return res;

Array.prototype.map = function(command){
  var outArray = [];
  this.each(function(x){
    outArray.push(command(x));
  });
  return outArray;
};

Array.prototype.map = function(f){
  var newArray = [];
  var i;
  for( i = 0; i<this.length; i++){
    newArray.push(f(this[i],i,this));
  return newArray;

var arr = [0,1,2,3,4];
var triple = function(x) { return x * 3; };
Array.prototype.map = function(f) {
    var newArr = [];
    for (var i = 0; i < this.length; i++) {
        newArr.push(f(this[i]));
    return newArr;
};
...

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