Caesar's Cipher (Need Help)

function rot13(str) { // LBH QVQ VG!
  str.split(" ");
  for(var i = 0; i < str.length; i++) {  
  return str; 

// Change the inputs below to test
rot13("SERR PBQR PNZC");

Trying to solve this one by turning the string into an array of letters and then converting them into their corresponding Unicode. Am I on the right track?

Yes, that’s a fine strategy, since you fundamentally want to treat characters as numbers.