Javascript effective Array shuffle

array_shuffle.js

Array.prototype.shuffle = function () {
  var randomIndex, temp, i = this.length;
  while (--i) {
    randomIndex = Math.floor(i * Math.random());
    if (randomIndex !== i) {
      temp = this[i];
      this[i] = this[randomIndex];
      this[randomIndex] = temp;
    }
  }
  return this;
};