Shuffle arrays

shuffle.js

shuffle = function (arr) {
    var newArr = [],
        origArr,
        len;

    if (!!arr && ) {
        origArr = arr.slice();
        len = arr.length;

        while (len) {
            newArr.push(origArr.splice(parseInt(Math.random() * len--), 1)[0]);
        }
    } else {
        return arr || null;
    }
    
    return newArr;
}