From: Robert Klemme <shortcutter@...>
Date: 2009-07-04T21:50:06+09:00
Subject: Re: How to remove/delete/destroy class variable in Ruby 1.9?

On 04.07.2009 14:06, David A. Black wrote:
> On Sat, 4 Jul 2009, dzw! wrote:
> 
>> Ok, code below shows better what I am talking about, I understand that
>> @@var is acting like global variable.
>> But how to get rid of it when is not needed anymore?

> You're trying to maintain and alter state on a per-class basis, which
> really means on a per-object (class object) basis. Class variables are
> not suited to that purpose; they are, as you say, really sort of
> vertical globals.
> 
> (In fact, I've always thought that $$var would be a better designation
> for class variables than @@var, because @@var makes it look like class
> variables have some kind of affinity with instance variables, which
> they definitely don't.)

The only commonality I can think of off the top of my head is the fact 
that you can use them from within instances much the same way as 
instance variables.

> Anyway -- I don't know of any way to undefine a class variable. I'd
> recommend using instance variables if you need per-class state.

My 0.02 EUR: the best way to get rid of class variables is to not use 
them in the first place. :-)

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/