if(0 == '%') echo "WTF, Php, why can't you compare things sanely?"
comparison, debugging, php
Solution
Using '===' (for exact, literal comparison -- the values must be the same type and also equal) instead of '==' solves this problem. With '==' it's trying to cast '%' to a number and 0 is the best it can do.
Problem
I just reduced a crazy bug to what's in the title of this question. I'm sure there's a Perfectly Reasonable Explanation for why Php thinks that 0 == '%' (or any other special character, I think). I thought it would be good to get that explanation on StackOverflow!