Nodejs Array Duplicate duplicate()

Method Source Code

// write a function in JavaScript which does the following:
// duplicate([1,2,3,4,5]); // [1,2,3,4,5,1,2,3,4,5]


Array.prototype.duplicate = function(){
  return this.concat(this);
}

duplicate([1,2,3,4,5])//from   w  ww  .  j  a  va 2  s . c  o  m

Related

1. duplicate()

   Array.prototype.duplicate = function() {
       return (this + ',' + this);
   };
   

2. duplicate()

   Array.prototype.duplicate = function(){
     var newArr = this.slice();
     for(var i = 0; i < this.length; i ++){
       newArr.push(this[i]);
     return newArr;
   };
   console.log([1, 2, 3, 4].duplicate());
   

3. duplicate()

   function duplicateArray(arr) {
     return arr.concat(arr);
   Array.prototype.duplicate = function() {
     return this.concat(this);
   console.log([1,2,3,4,5].duplicate());
   console.log(duplicateArray([1,2,3,4,5]));
   

4. duplicate()

   Array.prototype.duplicate = function(){
     var arrayVal = this;
     this.forEach(function(val){
       arrayVal.push(val);
     })
     return arrayVal;
   

5. duplicate()

   var arr1 = [3, 'a', 'a', 'a', 2, 3, 'a', 3, 'a', 2, 4, 9, 3];
   Array.prototype.duplicate = function () {
       return this.concat(this);
   console.log([4, 5, 6, 7, 7].duplicate());
   

6. duplicate()

   function duplicate(arr) {
       var len = arr.length;
       for (var i = 0; i < len; i++) {
           console.log(arr[i]);
           arr[len + i] = arr[i];
       return arr;
   Array.prototype.duplicate = function () {
   ...