It can happen in a few languages, but PHP is notably more aggressive in trying to convert to int. Actually a common way to grief new websites is to try to regi

It can happen in a few languages, but PHP is notably more aggressive in trying to convert to int. Actually a common way to grief new websites is to try to register '0' as a username. `if (string)` is a common way to check for null, and '0' will often fail.