Don't know where to start for key wraparound in vigenere pset2

Question

First off, I've done everything for Vigenere except wraparound the code. So if I am printing something that is of equal or lesser length to the key, it works perfectly. Problem is I don't even know where to begin for code wraparound. I have a feeling I need a separate array counter for the key than i that I am using to advance to the next character in the message, and then every time (let's call the new array counter j) j = i it would reset to 0 until i is done. I have no idea how to do that though...

anyway, here is the code

http://pastebin.com/0KGjQFQ4

Answer 1

When I did this (yesterday) I obtained the string length of the key, then obtained the modulus of the length of the key.

j % lengthOfKeyVariable

then I incremented j, as long as you don't reset J within the for loop it should allow you to select the correct char of the string