<p>需要排序的数组：[20, 3, 7, 9, 8, 8, 10, 89, 72, 3]</p>
<p>排序的结果：<span id="j-arr"></span></p>

function quickSort (arr = []) {
  if (arr.length <= 1) {
    return arr
  } else {
    let base = arr.shift()
    let less = arr.filter((curr) => { return curr <= base })
    let greater = arr.filter((curr) => { return curr > base })
    return quickSort(less).concat([base], quickSort(greater))
  }
}

let newArr = quickSort([20, 3, 7, 9, 8, 8, 10, 89, 72, 3])
document.getElementById('j-arr').innerText = JSON.stringify(newArr)