Factorialize a Number - Question about 0

1

Morning guys,

I’ve just finished the Factorialize a Number bonfire, and I was hoping to clarify one of the test requirements. To pass, you need to make sure factorialize(0) returns 1, but I’m having trouble understanding why that is.

Since factoring is 1 * 2 * 3… up until n, shouldn’t this make factoring 0 return 0?

Here’s how I got past the test, but I’m not confident I completed the task with a solid understanding:

function factorialize(num) {
  //var to be updated in loop.
  var updateVal = num;

  for (var i = 1; i != num; i++) {
    updateVal *= i;
  }
  
  num = updateVal;
  
  //checking if num was zero
  if (num === 0) {
    return 1;
  } else {
    return num;
  }
}
2

This article explains why factorial 0! = 1.

2 Likes
3

Thanks Reggie! That makes perfect sense.