function quickSort(arr) {

  if (arr.length <= 1) {

    return arr;

  }

  const pivot = arr[arr.length - 1];

  const left = [];

  const right = [];

  for (let i = 0; i < arr.length - 1; i++) {

    if (arr[i] < pivot) {

      left.push(arr[i]);

    } else {

      right.push(arr[i]);

    }

  }

  return [...quickSort(left), pivot, ...quickSort(right)];

}

​

// Example usage:

const array = [35, 2, 12, 6, 21, 14];

console.log(quickSort(array)); // Output: [2, 6, 12, 14, 21, 35]

const quicksort = arr =>

  arr.length <= 1

    ? arr

    : [

        ...quicksort(arr.slice(1).filter((el) => el < arr[0])),

        arr[0],

        ...quicksort(arr.slice(1).filter((el) => el >= arr[0])),

      ];

function quickSort(arr) {

  if (arr.length <= 1) {

    return arr;

  }

​

  const pivot = arr[arr.length - 1];

  const left = [];

  const right = [];

​

  for (let i = 0; i < arr.length - 1; i++) {

    if (arr[i] < pivot) {

      left.push(arr[i]);

    } else {

      right.push(arr[i]);

    }

  }

​

  return [...quickSort(left), pivot, ...quickSort(right)];

}

​

// Test the quickSort function

const arr = [5, 2, 9, 1, 7, 6, 4, 8, 3];

const sortedArr = quickSort(arr);

console.log(sortedArr);