Trying to find factors of a number in JS

Question

I am just starting JS, and understand the concept of finding a factor. However, this snippet of code is what I have so far. I have the str variable that outputs nothing but the

Answer 1

function factorialize(num) { 
 if(num === 0)
   return 1; 
 var arr = []; 
 for(var i=1; i<= num; i++){
   arr.push(i);
 } 
 num = arr.reduce(function(preVal, curVal){
   return preVal * curVal;
 });

  return num;
}

factorialize(5);