From: Lyle Johnson <lyle@...>
Date: 2003-11-17T10:25:44+09:00
Subject: Re: Ruby/Tk Some Basic Questions

David D'Andrea wrote:

> If you'll forgive another newbie question:
> 
> What is an abstract class?
> 
> I think of classes as abstract already, and objects as concrete.  Maybe 
> an abstract class is one that never gets instantiated, but is always 
> further specified / subclassed before being used?

Yes, your guess is correct. Abstract base classes are never themselves 
instantiated, but rather provide a set of basic functionality that their 
(concrete) subclasses use.