SOURCE

function shuffle(arr) {
// let arr = [].concat(arrp)
  let i = arr.length;
  while (i) {
    const r = Math.floor(Math.random() * i--);
    console.log(r);
    [arr[i], arr[r]] = [arr[r], arr[i]];
  }
  return arr
}

const arr = [1,2,4,6,7,8,6]
console.log(arr)
console.log(shuffle(arr))