Zach Dennis
5/29/2005 4:34:00 AM
Navya Amerineni wrote:
> Hi caio,
>
> thanks for your valuble suggestion and it works
> great.I have one another silly question
>
> this is the code
> class Song
> def initialize(name, artist, duration)
> @name=name
> @artist=artist
> @duration=duration
> end
> def myclass_function
> puts "this is my first class"
> end
> def to_s
> puts "Song: #@name--#@artist (#@duration)"
> end
> end
> class Karaokesong
> def initialize(name, artist, duration, lyrics)
> super(name, artist, duration)
> @lyrics=lyrics
> end
> def to_s
> puts "Song: #@name--#@artist (#@duration)"
> end
> end
>
> the following is the error
>
> "myfirstprojectfile:16:in `initialize': wrong number
> of arguments (3 for 0) (ArgumentError)"
>
> the error is with super.
>
> can you explain why it is.
Change the following line:
class Karaokesong
to:
class Karaokesong < Song
That will make Karaokesong a subclass of Song. When you call super it
will call Song's initialize method which takes 3 arguments. When it
doesn't subclass Song, Karaokesong by default will subclass from Object.
Object itself doesn't take any arguments in it's constructor.
HTH,
Zach