CodeAcademy - Recursion in Javascript Sec 2/5, Ex 5/5

gistfile1.js

/*
Now that we've covered the bare essentials, try rebuilding the
factorial() function we've been working on, but this time write 
it all from scratch. To help you along, here are five questions 
that you can use whenever using recursion in your code:

-What is/are the base case(s)?
-What is/are the recursive case(s)?
-Have I included any other necessary termination condition(s)?
-Do the statements in the function lead to the base case?
-Does the recursion build on the base case until the desired 
result is returned by the function?

Define the base case. Since a factorial is multiplying an 
integer by each integer between it and one, the base case is one.

Define the recursive case. What action needs to be performed 
over and over again in order to achieve the desired result?

Write any termination conditions to prevent the function from 
accepting arguments that would trigger an error.

*/

function factorial(n) {
   //termination condition
   if (n<0) {
   console.log("Only non-negative numbers allowed");
   return;
   }
   //base case
   if (n===1) {
   return 1;	
   }
  //recursion
  return n * factorial(n-1);
  
}