From: uncutstone wu <uncutstone@...>
Date: 2006-05-21T13:47:26+09:00
Subject: Re: Class variables and class instance variables in Pickaxe

James Britt wrote:

> A class is also an object; it's an instance of Class.  Since it is an
> object it may have its own instance variables.    Class variables are
> available to the class and to instances of that class; class instance
> variables are only visible to the class itself (not to instances of that
> class).  (Yeah, it can be confusing at first.)
> 
> 
> class Foo
>    @@cls_var = 123
>    @cls_instvar = 'abc'
> 
>    def test
>      p @@cls_var
>      p @cls_instvar
> 
>    end
> 
>    def self.test
>      p @@cls_var
>      p @cls_instvar
>    end
> end
> 
> 
> puts( "Foo is a #{Foo.class}")
> 
> f = Foo.new
> f.test
> Foo.test

Very thanks, it's quite clear now.

uncutstone

-- 
Posted via http://www.ruby-forum.com/.