quicksortArray.js

function quicksort(arr){
  if(arr.length){
    var x = arr.shift(),
        smallersort = quicksort(arr.filter(function (item){
          return item<x;
        })),
        biggersort = quicksort(arr.filter(function (item){
          return item>=x;
        }));
    return smallersort.concat([x],biggersort);
  } else {
    return [];
  }
}