From: Massimiliano Mirra <list@...>
Date: 2001-11-17T09:03:40+09:00
Subject: [ruby-talk:25688] Re: Something strange with Ruby's inheritance mechanism

On Sat, Nov 17, 2001 at 01:20:26AM +0900, Eric Jacoboni wrote:
> In fact, "my head" has some problem to justify that there is two
> objects of different classes that can be assigned to each other (i'm
> rather experienced with strong typing languages).

There are no two objects being assigned to each other in your example,
there is just one variable to which you first assign a reference to an
object, then to another one.

anEmployee = Employee.new 
# the anEmployee variable now contains a reference to an object of
# class Employee

aString = String.new
# the aString variable now contains a reference to an object of class
# String

anEmployee = aString
# now the anEmployee contains the same reference contained in the
# class aString

Variables are just names.  Maybe it will be clearer to you if you
choose more "neutral" names, such as x, y... that do not make you
think that a variable must be bound to the first thing it is assigned.

BTW I come from an Object Pascal background so I fully sympathize. :-)
And you don't need strong typing at all to teach OOP concepts.

Massimiliano