From: zdennis <zdennis@...>
Date: 2006-04-08T02:19:37+09:00
Subject: Re: Simple Question About Deleting Instances

Nathan Olberding wrote:
> zdennis wrote:
>> Can you post code along with your questions ? It makes it so much easier
>> to help.
> 
> class A
>    @@a = 1
>    @b = 2
>    def say_stuff()
>       puts @@a # Works
>       puts @b  # Doesn't work
>    end
> end

You are creating an instance variable @b on your class A. The class A is
an instance of the class Class, so it to can have instance variables.

You want to define your instance variable @b inside of your initialize
method, or you want to use attr_* methods to do this for you:

  class A
    @@a = 1

    def initialize
      @b = 2
    end

    def say_stuff
       puts @@a
       puts @b
    end
  end

  a = A.new
  a.say_stuff

Or:

  class A
    attr_accessor :b

    @@a = 1

    def initialize
      @b = 2
    end

    def say_stuff
       puts @@a
       puts @b
    end
  end

  a = A.new
  a.b = 10
  a.say_stuff

You should really check this stuff out in IRB as well. Open a shell or
cmd.exe and type 'irb'.

Zach