Nodejs Array ForEach _forEach(callback)

Method Source Code

'use strict';/*  www .  j a v  a  2s. c o  m*/

const testArray = ['Bob', 'Mary', 'Lee', 'Snake', 'Jimbob'];

Array.prototype._forEach = function(callback) {

  for (let i = 0; i < this.length; i++) {
    callback(this[i]);
  }
  return this;
};

// Simply console logging the array
testArray._forEach( item => {
  console.log(item);
});

// Splitting the array
testArray._forEach( item => {
  let newArray = item.split('');
  console.log(newArray);
  return newArray;
});

// Splitting and reversing the array
testArray._forEach( item => {
  let newArray = item.split('').reverse();
  console.log(newArray);
  return newArray;
});

// Adding the #1 to each item
testArray._forEach( item => {
  let newArray = [];
  newArray.push(item + 1);
  console.log(newArray);
  return newArray;
});

Related

1. foreach( callback )

   Array.prototype.foreach = function( callback ) {
     for( var k=0; k<this .length; k++ ) {
       callback( k, this[ k ] );
   Object.prototype.foreach = function( callback ) {
     for( var k in this ) {
       if(this.hasOwnProperty(k)) {
        callback( k, this[ k ] );
   ...
   

2. foreach(callback)

   Array.prototype.foreach = function(callback) {
     for(var i in this) if(this.hasOwnProperty(i)) callback(this[i]);
     return this;
   

3. foreach(callback)

   Array.prototype.foreach = function(callback)
       for (var i = 0; i < this.length; i++)
           callback(this[i])
   Array.prototype.getRandomIndex = function()
       var n = Math.floor(Math.random()*this.length)
       return n
   Array.prototype.getRandomElement = function()
       var n = this.getRandomIndex()
       return this[n]
   var Arrays = {
       remove: function(obj, arr) {
           var index = arr.indexOf(obj);
           if (index != -1)
               arr.splice(index, 1);
       },
       contains: function(obj, arr) {
           return arr.indexOf(obj) > -1;
       },
       addIfAbsent: function(obj, arr) {
           if (!Arrays.contains(obj, arr)) {
               arr.push(obj);
       },
       getRandomElement: function(arr) {
         var n = this.getRandomIndex(arr);
         return arr[n];
       },
       getRandomIndex: function(arr) {
        var n = Math.floor((Math.random()*arr.length));
         return n;
   };
   

4. foreach(fn)

   Array.prototype.foreach = function(fn) {
     for (let i = 0; i < len; i++)
       fn(this[i], i, this);
   };
   

5. foreach(func)

   Array.prototype.foreach = function(func) {
       var length = this.length;
       for ( var i = 0; i < length; i++ ) {
           func(this[i]);
   };