Calculate a factorial Javascript code example

Example 1: javascript factorial

function factorial(n) {
  if (n < 0) return;
  if (n < 2) return 1;
  return n * factorial(n - 1);
}

Example 2: javascript factorial stack

function factorial(n) {
    let s = new Stack();
    while (n>1){
        s.push(n--);
    }
    let product = 1;
    while (s.length() > 0) {
        product *= s.pop();
    }
    return product;
}