Nodejs Array Shuffle shuffle()

Method Source Code

/**/*  ww w  .  j  ava 2  s  .c o  m*/
 * Shuffle a given array
 * @param {array} array Array to be shuffled
 * @return {array} Suffled array
 */
Array.prototype.shuffle = function () {
    let array = this, arraylength = array.length, randomIndex, temp;

    while (arraylength) {
        randomIndex = Math.floor(Math.random(arraylength) * arraylength--);

        temp = array[arraylength];
        array[arraylength] = array[randomIndex];
        array[randomIndex] = temp;
    }

    return array;
}

// Test 1
console.log([].shuffle());
// Test 2
console.log([0].shuffle());
// Test 3
console.log([1].shuffle());
// Test 4
console.log([1,2].shuffle());
// Test 5
console.log([1,2,3].shuffle());
// Test 6
console.log([1,2,3,4,5,6,7,8,9,10,-1].shuffle());

Related

1. shuffle()

   Array.prototype.shuffle = function() {
     var currentIndex = this.length, temporaryValue, randomIndex;
     while (0 !== currentIndex) {
       randomIndex = Math.floor(Math.random() * currentIndex);
       currentIndex -= 1;
       temporaryValue = this[currentIndex];
       this[currentIndex] = this[randomIndex];
       this[randomIndex] = temporaryValue;
   

2. shuffle()

   Array.prototype.shuffle = function() {
       if (Object.prototype.toString.call(this) !== '[object Array]') {
           throw new TypeError("`this` must be Array, not " + typeof this);
       var length = this.length;
       for (var i = length - 1; i >= 0; i--) {
           var randomIndex = Math.floor(Math.random() * length),
               temp = this[i];
           this[i] = this[randomIndex];
   ...
   

3. shuffle()

   Array.prototype.shuffle = function(){
     var length = this.length;
     var i, j, temp;
     for(i = length - 1; i >= 0; i--){
       j = Math.floor(Math.random()*(i+1));
       temp = this[i];
       this[i] = this[j];
       this[j] = temp;
     return this;
   };
   var testArray = [1,2,3,4,5,6,7,8,9,10];
   console.log(testArray.shuffle());
   console.log(testArray);
   

4. shuffle()

   Array.prototype.shuffle = function(){
     var result = [];
     while(this.length > 0 ){
       result.push( this.splice(Math.floor(Math.random() * this.length), 1)[0] );
     return result;
   };
   

5. shuffle()

   Array.prototype.shuffle = function(){
     for (var i = 0; i < this.length; i++){
         var a = this[i];
         var b = Math.floor(Math.random() * this.length);
         this[i] = this[b];
         this[b] = a;
   function shuffleProperties(obj) {
   ...
   

6. shuffle()

   'use strict';
   Array.prototype.shuffle = function() {
     var arr = this.slice(0);
     var counter = this.length,
       temp, index;
     while (counter > 0) {
       index = Math.floor(Math.random() * counter);
       counter--;
       temp = arr[counter];
   ...
   

7. shuffle()

   Array.prototype.shuffle=function() {
     this.sort(function() {return Math.random()-0.5; });
   

8. shuffle()

   Array.prototype.shuffle = function() {
   var s = [];
   while (this.length) s.push(this.splice(Math.random() * this.length, 1)[0]);
   while (s.length) this.push(s.pop());
   return this;
   

9. shuffle()

   Array.prototype.shuffle = function(){
     var i=this.length,j,t;
     while(i--)
       j=Math.floor((i+1)*Math.random());
       t=this[i];
       this[i]=this[j];
       this[j]=t;
     return this;
   };