基本过程

1. 选取数组中的一个元素作为基准(pivot)

2. 按照基准将数组分区，左区全部小于基准，右区全部大于基准，使用方法为原地置换(swap in place)

3. 对左右分区递归使用1和2步，直至左右分区只有一个或零个元素，排序完成

JavaScript实现

function fQuickSort(arr,low,high) {    if(low > high){        return;    }    if(low < 0){        throw new Error('low should be great than zero')    }    if(high >= arr.length){        throw new Error('high should be less than array\'s length')    }    var pivotIndex = fSwapInPlace(arr,low,high);    fQuickSort(arr,low,pivotIndex-1);    fQuickSort(arr,pivotIndex+1,high);}function fSwapInPlace(arr,low,high){    var pivot = arr[low];    while (low < high) {        while(low < high && arr[high] > pivot){            high--;        }        arr[low] = arr[high];        while(low < high && arr[low] <= pivot){            low++;        }        arr[high] = arr[low];    }    arr[low] = pivot;　 //stop at pivot place,low equals pivot index    return low;}

 JavaScript数组方式实现

function quickSort(arr){    if(arr.length <= 1) return arr;    var index = Math.floor(arr.length/2);    var key = arr.splice(index,1)[0];    var left = [],right = [];    arr.forEach(function(v){        v <= key ? left.push(v) : right.push(v);    });    return quickSort(left).concat([key],quickSort(right));}