From: Robert Dober <robert.dober@...>
Date: 2006-04-21T18:29:29+09:00
Subject: Re: how to figure out what class a method is in for a *class method*?

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On 4/21/06, Andy Gimblett <A.M.Gimblett@swansea.ac.uk> wrote:
>
> I have a related question - a similar problem to the one just given,
> but that solution doesn't fit here because I don't just want the class
> name - I want an attribute associated with the class, which subclasses
> can override.
>
> I've tried doing this using class variables, but it doesn't work:
>
> --
>
> class Animal
>   @@sound =3D "nothing"
>   def to_s
>     "I say " + @@sound
>   end
> end
>
> class Cat < Animal
>   @@sound =3D "miaow"
> end
>
> class Dog < Animal
>   @@sound =3D "woof"
> end
>
> fudge =3D Cat.new()
> puts fudge
>
> tip =3D Dog.new()
> puts tip
>
> --


class Animal
 @sound =3D "nothing"
 class << self
    attr_accessor :sound
 end
 def to_s
   "I say " + self.class.sound
 end
end

class Cat < Animal
 self.sound =3D "miaow"
end

class Dog < Animal
 self.sound =3D "woof"
end

fudge =3D Cat.new()
puts fudge

tip =3D Dog.new()
puts tip

That's how ruby treats it, there are some who argue that @@ should go away,
maybe they are right.

Hope that helps
Robert

>
> --
> Andy Gimblett
> Computer Science Department
> University of Wales Swansea
> http://www.cs.swan.ac.uk/~csandy/
>
>


--
Deux choses sont infinies : l'univers et la b=EAtise humaine ; en ce qui
concerne l'univers, je n'en ai pas acquis la certitude absolue.

- Albert Einstein

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