Nodejs Array Multiply multiplyByTwo()

Method Source Code

Array.prototype.multiplyByTwo = function() {
  var newArr = [];

  for (var i = 0; i < this.length; i++) {
    newArr.push(this[i] * 2)//  w ww .  ja v  a  2s.co  m
  }

  return newArr;
};

console.log([1, 2, 3].multiplyByTwo());


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

[1, 2, 3].myEach( function(x) { console.log(x) })


Array.prototype.myMap = function(func) {
  var newArr = [];

  this.myEach(function(x) {
    newArr.push(func(x));
  });

  return newArr;
}

console.log([1, 2, 3].myMap(function(x) {
  return x * 3;
}));


Array.prototype.myInject = function(func) {
  var acc = this[0];

  this.slice(1, this.length).myEach(function(x) {
    acc = func(acc, x);
  });

  return acc;
};

console.log([1, 2, 3, 4].myInject(function(acc, x) {
  return acc + x;
}));

Related

1. mult2()

   Array.prototype.mult2 = function() {
       for (var i = 0; i < this.length; i++) {
           this[i] = this[i] * 2;
   };
   

2. multipleConcat()

   Array.prototype.multipleConcat = function() {
       var initialArray = arguments[0];
       if (arguments.length > 0) {
         for (var i = 1, arrayCount = arguments.length; i < arrayCount; i++ ) {
           initialArray.push.apply(initialArray, arguments[i]);
         return initialArray;
   };
   ...
   

3. multiples(multiple)

   Array.prototype.multiples = function(multiple) {
     var multiples = [];
     for (var i = 0; i < this.length; i++){
       multiples.push(this[i] * multiple);
     return multiples;
   console.log([1,2,3,4,5].multiples(5));
   Array.prototype.myEach = function(someFunction){
   ...
   

4. multiply(a2)

   Array.prototype.multiply = function(a2) {
     var l1 = this.length;
     var l2 = a2.length;
     var len = (l1 < l2 ? l1 : l2);
     var result = new Array(len);
     for (var i = 0; i < len; i++) {
       result[i] = this[i] * a2[i];
     return result;
   ...
   

5. multiply(n)

   Array.prototype.multiply = function(n){
     results = []
     for (var i = 0; i < this.length; i++){
       for (var j = 0; j < n; j++){
         results.push(this[i])
     return results
   

6. multislice(ranges)

   Array.prototype.multislice = function(ranges) {
     if(typeof ranges === 'undefined')
       throw Exception("Ranges have to be defined!");
     if(typeof ranges !== 'object') 
       throw Exception("You have to pass an array!");
     return ranges.map(el => this.slice(el.from, el.to));
   };
   

7. multislice(ranges)

   'use strict';
   var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { 
     return typeof obj; 
     } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol ? "symbol" : typeof obj; };
   Array.prototype.multislice = function (ranges) {
     var _this = this;
     if (typeof ranges === 'undefined') throw Exception("Ranges have to be defined!");
     if ((typeof ranges === 'undefined' ? 'undefined' : _typeof(ranges)) !== 'object') throw Exception("You have to pass an array!");
     return ranges.map(function (el) {
   ...
   

8. multisplice()

   Array.prototype.multisplice = function(){
     var args = arguments[0], 
       res = [];
     args.sort( function(a, b){
        return a - b;
      });
     for(var i = 0; i < args.length; i++){
       var index = args[i] - i;
       res.push( this.splice(index, 1)[0] );
   ...
   

9. mutilate(start, end)

   var arr = ["Devin Hardy", "Seth Rollins", "Cole Sprouse"];
   Array.prototype.mutilate = function(start, end) {
     var newArr = [];
     if (end > this.length || start > this.length) {
       throw new Error("Invalid opperation.");
     } else {
       arr2 = this.slice(start, end);
       newArr.push(arr2);
     return newArr;
   };