From: Gavin Kistner <gavin.kistner@...>
Date: 2006-10-06T04:17:46+09:00
Subject: Re: question mark at end of method name

From: py [mailto:codecraig@gmail.com] 
> what does the question mark at the end of a method name represent?
> i've seen what ! does....what is ?  

It is a convention that indicates that the method is likely to return a
boolean value.

! is a convention that indicates that the method is 'dangerous',
possibly modifying the receiving instance or doing other drastic things.