Shuffle Array

function shuffle(arr) {
  for (let i = arr.length - 1; i > 0; i--) {
    const j = Math.floor(Math.random() * (i + 1));
    [arr[i], arr[j]] = [arr[j], arr[i]];
  }
 
  return arr;
}

const arr = [1, 2, 3, 4, 5];
shuffle(arr); // e.g. [5, 3, 2, 4, 1]