From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2010-10-11T16:59:28+09:00
Subject: Re: how do i add an instance variable to a class in Ruby

On Mon, Oct 11, 2010 at 9:20 AM, Amit Tomar <amittomer25@yahoo.com> wrote:
> Thanks all for your response ,what am doing wrong is ,using
>
> def initialize1
>  @a=10
>
> end
>
>  instead of initialize am using initialize1 but what if i have some
> other function instead initialize ,then how could access this variable
> @a???

In Ruby, instance variables are created the first time you assign them
some value. It can be done in the initialize method or in any other
method:

class A
  def a=(value)
    @a = value
  end
  def a
    @a
  end
end

a = A.new
a.a = 3
puts a.a

Now, if you try to access it before setting it, you will get nil:

a = A.new
puts a.a

Jesus.