From: Robert Klemme <shortcutter@...>
Date: 2007-03-03T22:15:06+09:00
Subject: Re: Question about attr_accessor

On 03.03.2007 13:55, Roland Swingler wrote:
> Hi,
> 
> I came across something unexpected today, and wondered if anyone could
> explain it to me. If I have this class:
> 
> class Foo
>   def initialize
>     @bar = 0
>   end
> 
>   attr_accessor :bar
> 
>   def add
>     bar += 1
>   end
> end
> 
> then the "add" function doesn't work - it complains about a nil
> object. You have to specifically put "self.bar += 1". Why is that - I
> thought that the "self" was implicitly there?

bar += 1 is translated to "bar = bar + 1".  When Ruby sees "bar =" it 
takes bar to be a local variable.  Hence you have to prefix with 
"self.".  See:
http://www.ruby-doc.org/docs/ProgrammingRuby/html/language.html#UO

Kind regards

	robert