#factorialize

Recursion is the method of calling a function inside of itself in order to perform a given action. In this example, we are factorializing a given number (multiplying the number by every number less than itself but greater than one). Recursion works here by simplifying the function which could be slightly longer by using a for loop).

function factorialize(num) {

 if(num === 0) {    return 1;}

 return num * factorialize(num - 1);

}

factorialize(5);

For loop (alt):

function factorialize(num) {  

      for (a = 1;num >= 1; num--) { 

         a = num * a;  

         }  

      return a; 

}