From: "Kroeger, Simon (ext)" <simon.kroeger.ext@...>
Date: 2006-07-12T17:44:03+09:00
Subject: Re: Weird behavior of case/when

 

> -----Original Message-----
> From: Nicolas Despr�s [mailto:nicolas.despres@gmail.com] 
> Sent: Wednesday, July 12, 2006 10:31 AM
> To: ruby-talk ML
> Subject: Weird behavior of case/when
> 
> I'm getting a very weird result using case/when.
> 
> $ cat test.rb
> def test(a)
>   case a.class
>   when Class
>     puts "class"
>   when String
>     puts "string"
>   else
>     puts "else"
>   end
> end
> 
> test(Float)
> test("hello")
> test(42)
> $ ruby test.rb
> class
> class
> class
> $ ruby --version
> ruby 1.8.4 (2005-12-24) [i686-linux]
> 
> I would have exepected the following output:
> 
> class
> string
> else
> 
> Does anyone have an explanation about this issue?
> 
> Cheers,

case uses === which is well defined for obj === class. 
What you do is checking the class of a.class which is a class itself.

To make it short: use 'case a' instead of 'case a.class'

cheers

Simon