From: Tobias Reif <tobiasreif@...>
Date: 2001-08-20T23:09:20+09:00
Subject: [ruby-talk:20023] Re: problem understanding class relationships

I wrote:

> >Thus all classes are in the same family
> >and thus @@ variables would be shared among all objects.
> >
> >Where am I erring?

Yukihiro Matsumoto wrote:

> Like constants, class variables must be assigned at the class/module
> top level, and shared among its subclasses.
> 
>   class Foo
>     @@foo = 43  # @@foo is assigned (declared) here.
>   end
> 
>   class Bar<Foo
>     def bar
>       p @@foo   # @@foo is available.
>     end
>   end
> 
>   class Baz<Object
>     def baz
>       p @@foo   # @@foo is NOT available here.
>     end
>   end

Is the following possible?

class Foo<Object
 @@foo = 86
end

This would make the @@ variable available in all classes.

Tobi