js中快速排序如何实现

Array.prototype.quickSort = function () {

  const rec = (arr) => {

    if (arr.length === 1) {

      return arr;

    }

    const left = [];

    const right = [];

    const mid = arr[0];

    for (let i = 1; i < arr.length; i += 1) {

      if (arr[i] < mid) {

        left.push(arr[i]);

      } else {

        right.push(arr[i]);

      }

    }

    return [...rec(left), mid, ...rec(right)];

  };

  const res = rec(this);

  res.forEach((n, i) => {

    this[i] = n;

  });

};

const arr = [2, 4, 5, 3, 1];

arr.quickSort();