Nodejs Array Map map(callback)

Method Source Code

Array.prototype.map = function (callback) {
  var mapped = [];

  function mutation(el) {
    mapped.push(callback(el));/*from ww w. jav a2  s.  co  m*/
  }

  this.each(mutation);
  //
  // this.each(function (el) {
  //   mapped.push(callback(el));
  // });

  return mapped;
};

Related

1. map(callback)

   Array.prototype.map = function (callback) {
       var obj = this;
       var value, mapped_value;
       var A = new Array(obj.length);
       for (var i = 0; i < obj.length; i++) {
           value = obj[i];
           mapped_value = callback.call(null, value);
           A[i] = mapped_value;
       return A;
   };
   var arr = [1, 2, 3];
   var new_arr = arr.map(function (value) {
       return value * value;
   });
   console.log(new_arr);
   

2. map(callback)

   Array.prototype.map = function(callback) {
     let res = [];
     this.forEach(el => res.push(callback(el)));
     return res;
   };
   let a = [1,2,3];
   let b = a.map(el => el * el);
   console.log(a);
   console.log(b);
   ...
   

3. map(callback)

   Array.prototype.map = function(callback){
     var a = 0,
       len = this.length,
       result = [];
     while(a < len){
       result.push(callback(this[a], a++, this));
     return result;
   };
   ...
   

4. map(callback)

   Array.prototype.map = function(callback){
       const newArr = []
       for(let i = 0; i < this.length; i += 1){
           let newValue = callback(this[i])
           newArr.push(newValue)
       return newArr
   var someArray = [1,2,3,4]
   ...
   

5. map(callback)

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

6. map(callback)

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

7. map(callback)

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

8. map(callback, thisArg)

   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;
   ...
   

9. map(callback, thisArg)

   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;
   ...