From: Robert Klemme <shortcutter@...>
Date: 2011-09-30T18:38:26+09:00
Subject: Re: What is the best way to invoke inhirited instance method within constructor?

On Fri, Sep 30, 2011 at 3:46 AM, Jones Lee <joneslee85@gmail.com> wrote:
> The question is as of the title. Say I have a simple example below:
>
>
> class Vehicle
>  attr_accessor :wheels
> end
>
> class Car < Vehicle
>  def initialize
>    self.wheels = 4
>  end
> end
>
> class Truck < Vehicle
>  def initialize
>    @wheels = 16
>  end
> end
>
> I am curious which way is considered correct or better to invoke
> wheels writer method of mother Vehicle?

Truck#initialize does not invoke any writer method at all but plain
assigns an instance variable @wheels.  If you have a writer method
then it is generally considered much more robust to use it (like you
did in Car#initialize) because the writer might do more than to just
assign to a local variable (e.g. validity checks which ensure the
value is an integer value and greater or equal to 0).

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/