From: Yukihiro Matsumoto <matz@...>
Date: 2008-07-04T23:35:26+09:00
Subject: Re: initialize and super with parameters

Hi,

In message "Re: initialize and super with parameters"
    on Fri, 4 Jul 2008 23:26:46 +0900, Andy Joel <ak_joel@hotmail.com> writes:

|Some example code
|
|class MySuperClass
|  def initialize *args
|    puts "In SuperClass initialize"
|  end
|end
|
|class MySubClass1 < MySuperClass
|  def initialize name
|    puts "In SubClass initialize: " + name
|    super
|  end
|end
|
|The super in the subclass will take with it any parameters that were
|sent to the initialize method, so this will throw an error as the
|initialize in MySuperClass does not accept the same number of
|parameters.
|
|This is surprisingly restrictive (given the nature of Ruby generally).
|If you are extending a class with a parameterless initializer, you
|cannot access the superclass initializer if you want to include a
|parameter.

Why not?  You can explicitly provide arguments to super, e.g.

  super(arg1, arg2)

to call a method of super class.  You can call it without any argument
by

  super()

note that it's different from "super".

							matz.