SOURCE

let testArr = [5, 17, 1, 33, 6, 20];
document.write(`Original Array is [${testArr}]<br/>`);
function quickSort(arr) {
    if (arr.length < 2) {
        return arr;
    }
    else {
        let baseElem = arr[Math.floor(arr.length/2)];
        let smallElem = arr.slice(1).filter(elm => elm < baseElem);
        let bigElem = arr.slice(1).filter(elm => elm >= baseElem);
        let result = [quickSort(smallElem).concat(baseElem).concat(quickSort(bigElem))];
        return result;
    }
}
let resultArr = quickSort(testArr);
document.write(`Ordered Array is[${resultArr}]`);