QuickSort (recursive, wasteful) in JavaScript

gistfile1.js

var n = 100, 
    arr = (function (l, r, i) { for (i = 0; i < l; r.push(i++)); return r;}(n, []));

// http://en.wikipedia.org/wiki/Quicksort
function quicksort(arr) {
    var pivot, 
        pi = Math.floor(Math.random() * arr.length), // Random pivot index
        below = [], 
        above = [], 
        i, l;

    if (arr.length < 2) return arr;

    pivot = arr.splice(pi, 1).pop();

    for (i = 0, l = arr.length; i < l; i++) {
        if (arr[i] < pivot) {
            below.push(arr[i]);
        } else {
            above.push(arr[i]);
        }
    }

    return [].concat(quicksort(below), pivot, quicksort(above));
}

// The shuffle-function can be found at https://gist.github.com/2043791
quicksort(shuffle(arr));