shuffle array

shuffle.js

function rand(min, max) {
  if (max === undefined) { max = min; min = 0; }
  return Math.floor(Math.random() * (max - min + 1)) + min;
}

function shuffle(array) {
  var sample = array.slice(0);
  var length = sample.length;
  var last = length - 1;
  for (var index = 0; index < length; index++) {
    var rand = Utils.rand(index, last);
    var temp = sample[index];
    sample[index] = sample[rand];
    sample[rand] = temp;
  }
  return sample;
}