Nodejs Array ForEach forEach(a)

Method Source Code

"use strict"/*from   w w w . j a  va  2  s. co  m*/

Array.prototype.forEach = function(a) {
   for (let i = 0; i < this.length; i++) a(this[i], i, this)
}

Related

1. forEach

   ===
   

2. forEach()

   Array.prototype.forEach = Array.prototype.forEach || _forEach
   Array.prototype.every = Array.prototype.every || _every
   Array.prototype.indexOf = Array.prototype.indexOf || function(member) {
     for(var idx = 0; idx < this.length; ++idx) {
       if(this[idx] === member) {
         return idx
     return -1
   ...
   

3. forEach(action, index)

   Array.prototype.forEach = Array.prototype.forEach || function(action, index) {
       for (var i=0,l=this.length; i<l; i++) {
           action(this[i], index);
   };
   

4. forEach(callback)

   Array.prototype.forEach = function(callback){
       let arr = this;
       for (var i = 0; i < arr.length; i++) {
           callback(arr[i], i, arr);
   

5. forEach(callback)

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

6. forEach(callback)

   Array.prototype.forEach = Array.prototype.forEach || function (callback) {
       var self = this;
       for (var i = 0; i < self.length; i++) {
           var item = self[i];
           callback(item, i, self);