Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!tut.cis.ohio-state.edu!rutgers!dptg!att!cbnewsl!dune
From: dune@cbnewsl.ATT.COM (Greg Pasquariello)
Newsgroups: comp.object
Subject: Re: What is OOP / OOD
Message-ID: <2109@cbnewsl.ATT.COM>
Date: 3 Oct 89 13:43:59 GMT
References: <1989Oct2.161552.14306@polyslo.CalPoly.EDU>
Reply-To: dune@cbnewsl.ATT.COM (Greg Pasquariello)
Organization: AT&T Bell Laboratories
Lines: 31

In article <1989Oct2.161552.14306@polyslo.CalPoly.EDU> jearls@polyslo.CalPoly.EDU (  Stupid  ) writes:
>Sorry if this doesn't belong here, but could someone please tell me
>exactly what IS Object Oriented Programming or Object Oriented Design ?

Welllll, I am not an expert (so flames will be automatically doused), but
here is what I know from working with C++ for about a year now.

Object Oriented Programming (also know as the buzz-word from hell), is
a method of developing software using some kind of object.  An object is
nothing more than a collection of data, and the code that operates on that
data, usually autonomously.  For instance, if I have an object that represents
a window, I do not have to store the window data, and I do not have to 
draw the window on the screen;  the window keeps it's own data, and I can
tell the window to draw itself on the screen.  This has the benefit of 
isolating instances of windows, among other things.

OO Design is the methodology used to design both objects, and applications
that use them.  It involves isolating the pieces of code that will be both
reusable and autonomous, and resolving the functionality and data of these
objects.  For instance, if I am designing a window system, I would decide 
that a window is an autonomous object that will be able to draw itself,
display bitmap data, and determine it's optimum size.  To this end, it will
need to keep it's own coordinates, length and width, the bitmap data, etc.
In addition I will need to define an interface to the application code that
will be consistent across instances of windows as well as flexible.

I feel as if I should recommend a book here, but I can't think of one off the
top of my head.  Hope this helps though!


-Greg