Quick Sort

Code

function quickSort(arr, left = 0, right = arr.length - 1) {
  let pivot;
  let partitionIndex;

  if (left < right) {
    pivot = right;
    partitionIndex = partition(arr, pivot, left, right);
    
   //sort left and right
   quickSort(arr, left, partitionIndex - 1)
   quickSort(arr, partitionIndex + 1, right)
  }
  return arr;
}
     
function partition(arr, pivot, left, right) {
  let pivotValue = arr[pivot];
  let partitionIndex = left;

  for (let i = left; i < right; i++) {
    if (arr[i] < pivotValue) {
      swap(arr, i, partitionIndex);

      partitionIndex++;
    }
  }

  swap(arr, right, partitionIndex);

  return partitionIndex;
}

function swap(arr, i, j) {
  let temp = arr[i];
  arr[i] = arr[j];
  arr[j] = temp;
}