JavaScript: Silly Array Shuffle

silly-array-shuffle.js

// Array.indexed(4) returns [0, 1, 2, 3]
Array.indexed = function(n) {
  var result = [];
  while (n--) {
    result[n] = n;
  }
  return result;
};

// Shuffle an array in a not too efficient way.
Array.prototype.shuffle = function() {
  return this.map(function(item) {
    return {value: item, toString: function() { return +this; }.bind(Math.random())};
  }).sort().map(function(item) {
    return item.value;
  });
};

Array.indexed(5).shuffle(); // something like [2, 3, 0, 1, 4]