Quick Sort (JS)

quick-sort.js

const quickSort = (items) => {
  if (!items || items.length < 2) {
    return items
  }

  const pivot = items[items.length - 1];
  const left = [];
  const right = [];

  for (let i = 0; i < items.length - 1; i++) {
    if (items[i] < pivot) {
      left.push(items[i])
    } else {
      right.push(items[i])
    }
  }

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

const elements = [7, 2, 4, 1, 6, 5, 0, 4, 2];
const sortedElements = quickSort(elements);
console.log('sortedElements : ', sortedElements); // [0, 1, 2, 2, 4, 4, 5, 6, 7]