From: John Legate <jl2351@...>
Date: 2006-09-13T12:23:27+09:00
Subject: Newbie Alert

I am a brand new Ruby beginner, and I have what is undoubtedly a 
painfully simple newbie question.

I'm starting my learning by using the online "Programming Ruby, HTML 
Help Edition (v0.3a)", and I'm having trouble getting one of the 
earliest code samples in the "Classes, Objects, and Variables" chapter 
to work.  Here is my slightly modified version (with line numbers added) 
of the tutorial code that I've saved in a file called RubyTutorial.rb:

01	class Song
02	  def initialize(name, artist, duration)
03	    @name     = name
04	    @artist   = artist
05	    @duration = duration
06	  end
07	  def to_s
08	    puts "Song: #{@name}--#{@artist} (#{@duration})"
09	  end
10	end
11
12	aSong = Song.new("My Way", "Sinatra", 225)
13	print "aSong.to_s ==> "
14	aSong.to_s
15
16	class KaraokeSong < Song
17	  def initialize(name, artist, duration, lyrics)
18	    super(name, artist, duration)
19	    @lyrics = lyrics
20	  end
21	  def to_s
22	    super + " [#{@lyrics}]"
23	  end
24	end
25
26	kSong = KaraokeSong.new("My Way", "Sinatra", 225, "And now, the...")
27	print "kSong.to_s ==> "
28	kSong.to_s



When I try to run this from the Windows XP Command Prompt I get the 
following result:

C:\Documents and Settings\jl2351\My Documents\Ruby_Scripts>ruby 
RubyTutorial.rb
aSong.to_s ==> Song: My Way--Sinatra (225)
kSong.to_s ==> Song: My Way--Sinatra (225)
RubyTutorial.rb:22:in `to_s': undefined method `+' for nil:NilClass 
(NoMethodError)
        from RubyTutorial.rb:28

C:\Documents and Settings\jl2351\My Documents\Ruby_Scripts>


Obviously the "kSong.to_s" call is supposed to be displaying the 
additional lyric information.  Since I have no clue, can someone tell me 
how to correct this?  And why is '+' erroring out as an undefined 
method?  And any other insights into this error that a rank beginner 
might find helpful?

Thanks much.

-- 
Posted via http://www.ruby-forum.com/.