From: Bertram Scharpf <lists@...>
Date: 2005-03-25T09:18:52+09:00
Subject: Re: Understanding instance variables

Hi,

Am Donnerstag, 24. M�r 2005, 03:30:28 +0900 schrieb ts:
> >>>>> "B" == Bertram Scharpf <lists@bertram-scharpf.de> writes:
> 
> B>     class <<c ; @x = 'X' ; end
> 
>  You are working with the singleton class (see what is the value of self
>  when you make the assignement to @x), use the singleton class
> 
> B>     puts c.instance_variables, c.instance_eval( '@x')
> B>     puts @x
> 
>    puts class <<c; self end.instance_variables, 
>           class <<c; self end.instance_eval( '@x')

That means all three of

    c's Singleton  <  C  <  Object

can have their own instance variables.

>> c=class C ; self ; end.new
>> s=class << C ; self ; end
>> [c,s,C,Object].zip( %w-I S C O-).each { |x,y| x.instance_eval '@x='+y.inspect }
>> [c,s,C,Object].collect { |x| x.instance_eval '@x' }
=> ["I", "S", "C", "O"]


Or is there something I missed?

Bertram


-- 
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de