From: Leslie Viljoen <leslieviljoen@...>
Date: 2006-07-26T04:05:50+09:00
Subject: Re: method self.a= and a= create different instance variables

On 7/25/06, dblack@wobblini.net <dblack@wobblini.net> wrote:
> Hi --
>
> On Wed, 26 Jul 2006, yuesefa wrote:
>
> > i try this in irb .
> >
> > irb(main):001:0> def a=(a)
> > irb(main):002:1>   @a=a
> > irb(main):003:1> end
> > => nil
> > irb(main):004:0> def a
> > irb(main):005:1>   @a
> > irb(main):006:1> end
> > => nil
> > irb(main):007:0> a=1
> > => 1
> > irb(main):008:0> a
> > => 1
> > irb(main):009:0> self.a=2
> > => 2
> > irb(main):010:0> a
> > => 1
> > irb(main):011:0> self.a
> > => 2
> >
> > a and a= should be private methods of Object. so call of a or self.a
> > should do the same thing. but it's not. i am now confused.
>
> When you write:
>
>    a = 1
>
> Ruby parses that as a local variable assignment.  In other words,
> methods ending in = always require that you provide an explicit
> receiver (in this case "self").

also,

@a

will give you the same as

self.a

which makes sense because you are "inside" the definition of Object:

irb(main):085:0> self
=> #<Object:0x277fa2c @a=7>

Les