Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!uw-beaver!cornell!rochester!udel!princeton!siemens!drexel!rickers
From: rickers@drexel.UUCP (Rick Wargo)
Newsgroups: comp.lang.c++
Subject: Re: oo definition request
Message-ID: <590@drexel.UUCP>
Date: 13 May 88 17:20:56 GMT
References: <4800021@uiucdcsm>
Organization: Drexel University, Phila., Pa.
Lines: 42

From article <4800021@uiucdcsm>, by shirley@uiucdcsm.cs.uiuc.edu:
> I would like people to give their MINIMAL definitions of 'object
> oriented programming'.  Also, what MUST a language  be to be called
> an 'oo language'.  Please also state the reference, if any, that 
> gave/influenced your definition.
> 
> Peter Shirley
> U of Illinois at CU

Byte Magazine, Volume 11, Number 8 (August 1986) had an article
written by Geoffrey Pascoe of DoD Computing Systems Research Division (MD) 
entitled "elements of Object-Oriented Programming."  In this article
he states that there are four (and possibly five) qualities a language
should exhibit to be considered object oriented.

    1) information hiding
       - insures reliability of software
       - reduces inter-dependencies
       - state of a software module contained in private
         variables, accessible from only within the scope
         of the module
       - most languages support information hiding, for example,
         static variables in functions in C
    2) data abstraction
       - programmer defines an abstract data type which consists of an
         internal representation and a set of routines to access and
         manipulate the data
    3) dynamic binding
       - poly-morphism - the same message can elicit a different response
         depending on receiver, this should be accomplished at run-time.
       - no need to modify existing code
    4) inheritance
       - sub and super classing
    5) and, automatic storage management
       - better know as garbage collection
       - should qualify as fifth important element

							Rickers
							..!drexel!rickers

P.S.  This is an excerpt from the notes of an informal class on object-
oriented programming which I had taught last year.