From: Robert Klemme <shortcutter@...>
Date: 2011-03-10T00:24:55+09:00
Subject: Re: Comparison between C++ and Ruby Variables

On Wed, Mar 9, 2011 at 3:56 PM, Mayank Kohaley <mayank.kohaley@gmail.com> wrote:
>>
>> You write "The Class variable in Ruby is similar to static member variable
>> of C++."  This is not true.
>
>
> Can you please explain how exactly it is different from static member
> variables of C++.

I am sorry, there is a ton of material on class variables and their
oddities online (even in the archives of this forum).  Please look it
up.

Basically you cannot do that with static member variables in C++:

16:23:10 Temp$ ruby19 cv.rb
B1
2
S1
2
B2
1
S2
1
16:23:13 Temp$ cat -n cv.rb
     1  class B1
     2    @@foo = 1
     3    def self.show; p @@foo; end
     4  end
     5  class S1 < B1
     6    @@foo = 2
     7    def self.show; p @@foo; end
     8  end
     9  class B2
    10  end
    11  class S2 < B2
    12    @@foo = 2
    13    def self.show; p @@foo; end
    14  end
    15  class B2
    16    @@foo = 1
    17    def self.show; p @@foo; end
    18  end
    19  [B1,S1,B2,S2].each do |cl|
    20    puts cl
    21    cl.show
    22  end
16:23:16 Temp$

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/