From: Jesse Merriman <jesse.d.merriman@...>
Date: 2007-05-11T02:39:51+09:00
Subject: Re: instance_variables doesn't return unassigned variables

On Thursday 10 May 2007 06:00, Bernd wrote:
> Hi,
> I wrote a code like this.
> 
> class ABC
>   attr_accesor :first, :second
> end
> 
> when I wrote the following:
> 
> x = ABC.new
> x.first = "test"
> puts x.instance_variables
> 
> the output was only
> 
> @first

You could deduce them by looking for methods that end in an equals:

irb(main):001:0> class ABC
irb(main):002:1>   attr_accessor :first, :second
irb(main):003:1> end
=> nil
irb(main):004:0> x = ABC.new
=> #<ABC:0xb7a02d48>
irb(main):010:0> x.methods.select { |m| /[\w_]+=$/.match m }
=> ["second=", "first="]

From there just strip of the = and prepend a @.


-- 
Jesse Merriman
jessemerriman@warpmail.net
http://www.jessemerriman.com/