This won't work. Both 0 (numeric) and '0' (string) == false, but never === false (because when you === you're checking that it's the same type). If you expect

This won't work. Both 0 (numeric) and '0' (string) == false, but never === false (because when you === you're checking that it's the same type). If you expect a string '0', simply check strlen($str) > 0. If the value could be numeric, use a (string) cast.