From: Enrique Comba Riepenhausen <ecomba@...>
Date: 2007-05-26T05:31:06+09:00
Subject: Re: printing nil objects

> ### code starts here ###
> c1 = Node.new(1,nil,nil)
> c2 = Node.new(2,nil,nil)
> c3 = Node.new(3,nil,nil)
>
> c1.setP1(c2)
> c1.setP2(c2)
> c2.setP1(c3)
>
>
> current = c1
> while current.getP1 != nil
>     print "value = #{current.getV}, pointer1 = #{current.getP1.getV},
> "
>     if current.getP2.getV != nil then print "pointer2 =
> #{current.getP2.getV}\n" else print "null\n" end
>     current = current.getP1
> end
> [/code]

Your problem lies exactly there. You are trying to make a method call  
(getV) on a nil object, and obviously it doesn't have the (getV)  
method...

Try the following

if current.getP2.nil? then....

That should work.

Cheers,

----
Enrique Comba Riepenhausen
ecomba@mac.com

I always thought Smalltalk would beat Java, I just didn't know it  
would be called 'Ruby' when it did.
-- Kent Beck