how to return the factorial of an integer in javascript code example

Example 1: javascript factorial

function factorialize(num) {
  if (num === 0 || num === 1)
    return 1;
  for (var i = num - 1; i >= 1; i--) {
    num *= i;
  }
  return num;
}
factorialize(5);

Example 2: factorial javascript function

function factorialize(num) {
  if(num < 2) return 1;
  return num *= factorialize(num - 1);
}