From: 7stud -- <bbxx789_05ss@...>
Date: 2007-11-01T09:03:28+09:00
Subject: Re: why, or when to, use a class method?

Thufir wrote:
> On Oct 31, 2:17 pm, 7stud -- <bbxx789_0...@yahoo.com> wrote:
> [...]
>> > Why use a class method in the first example, though?
>>
>> So that you can check whether a Song is too long without having to
>> create a SongList object:
> [...]
> 
> What would be a case where there's a SongList object, though? 


class Song
  attr_accessor :duration

  def initialize(len)
    @duration = len
  end
end

class SongList
  MaxTime = 5*60
  attr_accessor :songs

  def initialize(song_arr)
    @songs = song_arr
  end

  def isTooLong(aSong)
    return aSong.duration > MaxTime
  end
end

my_playlist = SongList.new([Song.new(10), Song.new(4)])
song = my_playlist.songs[0]
puts my_playlist.isTooLong(song)





> Or, if
> there are class methods then generally there won't be objects of that
> class?
> 

If you will never have a need to create objects of the class, then I 
think you might just create a Module.  On the other hand creating a 
class where you can call class methods without objects and create 
objects and call instance methods gives you more options.  More options 
allows more flexibility.
-- 
Posted via http://www.ruby-forum.com/.