Shuffle a Deck of Cards

shuffle.js

var shuffle = function(arr) {
    var rand, temp;
    //loop through array and swap out value at random position
    //with value at iteration position of array
    for (var i = 0; i < arr.length; i++) {
        //generate random number between 0 and length of array.
        rand = Math.floor(Math.random() * arr.length);
        temp = arr[i]; //store value of arr[i] to swap later
        arr[i] = arr[rand]; //set arr[i] to random position value
        arr[rand] = temp; //replace with temp
    }
    return arr;
};

//tests
console.log(shuffle([1, 2, 3, 4, 5, 6, 73, 13, 20, 32, 33, 14, 12, 24]));
//[ 3, 14, 4, 32, 12, 1, 2, 13, 73, 33, 24, 6, 20, 5 ]
//[ 20, 4, 2, 1, 3, 5, 24, 73, 32, 12, 14, 33, 13, 6 ]
//[ 2, 5, 24, 1, 14, 32, 33, 20, 3, 12, 13, 4, 73, 6 ]
//[ 3, 5, 2, 1, 33, 4, 20, 6, 14, 73, 32, 24, 12, 13 ]