From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2012-06-30T00:57:36+09:00
Subject: Re: Accessor Methods with a Twist

On Fri, Jun 29, 2012 at 5:33 PM, Doug Jolley <lists@ruby-forum.com> wrote:
> I am surprised that the code shown below returns, 'Doug'.  I would
> expect that it would return, 'Fred'.  Can someone please tell me why?
>
> @name = 'Doug'
>
> def name=(name)
>  @name = name
> end
> def name()
>  return @name
> end
>
> name=('Fred')
> puts(name())


name=('Fred')  is interpreted as an assignment to a local variable
called name, not the call to the method. When you have an
"assignment-like" method (a method ending in the equals sign), you
have to use self. to call it, otherwise Ruby will think you are
assigning to a local variable:

1.9.2p290 :001 > def name=(name)
1.9.2p290 :002?>   @name = name
1.9.2p290 :003?>   end
 => nil
1.9.2p290 :004 > defined? name
 => nil
1.9.2p290 :005 > name=('fred')
 => "fred"
1.9.2p290 :006 > @name
 => nil
1.9.2p290 :007 > name
 => "fred"
1.9.2p290 :008 > self.name=('fred')
 => "fred"
1.9.2p290 :009 > @name
 => "fred"

Jesus.