From: reavey <reavey@...>
Date: 2003-02-19T09:31:21+09:00
Subject: help: append error on Array push

hi
I get an error
"NameError: undefined method 'push' for nil from append"
as I'm working thru the Prag prog ruby book.
"""We'll start our class with a basic initialize method, which creates 
the Array we'll use to hold our songs and store a reference to it in the 
instance variable @songs

class SongList
    def initialize
      @songs = Array.new
    end
end

The SongList#append method adds the given song to the end of teh @songs 
array. It also
returns self, a reference to the current SongList object. This is a 
useful convention, as it allows us to chain together multiple calls to 
appand...

class Songlist
       def append(aSong)
        @songs.push(aSong)
        self
    end
end

list = SongList.new
list.
    append(Song.new('title1', 'artist1', 1)).
    append(Song.new('title2', 'artist2', 2))      """

reports the error.
I've worked through all the example code and have been very impressed. 
 It is
very instructive and is the only book I've seen that tries to teach 
using a real model.

I'm writting all the code in irb.  Also, a test like
cSong = Song.new('title', 'artist', 245)
works fine.