Nodejs Array Shuffle shuffle()

Method Source Code

/**/*from  www  .  j av a 2s. c o  m*/
 * Performs a Fisher Yates shuffle on the array
 * @param {Array} array to shuffle
 */
Array.prototype.shuffle = function () {
    var i = this.length;
    while (1 < i--) {
        // generate random integer in the range [0,i]
        var j = Math.floor(Math.random() * (i+1));
        var a_j = this[j];
        this[j] = this[i];
        this[i] = a_j;
    }
};

Related

1. shuffle()

   Array.prototype.shuffle = function () {
     var input = this;
     var cnt = 1;
     for (var i = input.length - 1; i >= 0; i--) {
       var randomIndex = Math.floor(Math.random(cnt++) * (i + 1));
       var itemAtIndex = input[randomIndex];
       input[randomIndex] = input[i];
       input[i] = itemAtIndex;
     return input;
   

2. shuffle()

   Array.prototype.shuffle = function () {
       var tmp, current, top = this.length;
       if (top) while(--top) {
           current = Math.floor(Math.random() * (top + 1));
           tmp = this[current];
           this[current] = this[top];
           this[top] = tmp;
       return this;
   ...
   

3. shuffle()

   Array.prototype.shuffle = function() {
       var i = this.length, j, temp;
       while ( --i > 0 ) {
           j = Math.floor( Math.random() * ( i +1 ));
           temp = this [j];
           this [j] = this [i];
           this [i] = temp;
       return this;
   ...
   

4. shuffle()

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

5. shuffle()

   Array.prototype.shuffle = function()
     for(var i=0; i<this.length; i++)
       this.swap(i, parseInt(Math.random() * this.length));
   };
   

6. shuffle()

   Array.prototype.shuffle = function() {
       var i = this.length
       if (i == 0) return this
       while (--i) {
           var j = Math.floor(Math.random() * (i + 1 ))
           var a = this[i]
           var b = this[j]
           this[i] = b
           this[j] = a
   ...
   

7. shuffle()

   Array.prototype.shuffle = function() {
     var i = this.length;
     if ( i == 0 ) return;
     while ( --i ) {
        var j = Math.floor( Math.random() * ( i + 1 ) );
        var tempi = this[i];
        var tempj = this[j];
        this[i] = tempj;
        this[j] = tempi;
   ...
   

8. shuffle()

   Array.prototype.shuffle = function() {
       var i = this.length, j, temp;
       while(--i>=0) {
           j=Math.floor(Math.random() * (i+1));
           temp = this[j];
           this[j] = this[i];
           this[i] = temp;
       return this;
   ...
   

9. shuffle()

   Array.prototype.shuffle = function() {
       var swapbucket = this.length, randomelem, tempswap, tempelem;
       while (swapbucket--) {
           randomelem = Math.floor(Math.random() * (swapbucket + 1));
           tempelem = this[randomelem];
           tempswap = this[swapbucket];
           this[randomelem] = tempswap;
           this[swapbucket] = tempelem;