Newsgroups: comp.lang.smalltalk
Path: cantaloupe.srv.cs.cmu.edu!europa.chnt.gtegsc.com!howland.reston.ans.net!ix.netcom.com!netcom.com!altinbay
From: altinbay@netcom.com (John Altinbay)
Subject: Re: Smalltalk terminology - Object, Class, and Instance
Message-ID: <altinbayDAu4o3.LHv@netcom.com>
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
References: <3shvfp$l9k@portal.gmu.edu> <DAsuBL.9Ir@mv.mv.com>
Date: Tue, 27 Jun 1995 14:09:38 GMT
Lines: 38
Sender: altinbay@netcom11.netcom.com

In article <DAsuBL.9Ir@mv.mv.com> rapp@lmr.mv.com (L. M. Rappaport) writes:
>mtran2@osf1.gmu.edu (My-Phuong L Tran) wrote:
>
>>I am very confused by the meanings of these three important terms in ST.
>>To give an example of the difficulties I would like to quote from a
>>typical book on Smalltalk, 'An Introduction to Object-Oriented
>>Programming and Smalltalk', by Lewis J.Pinson and Richard S.Wiener,
>>which by the way is *fantastic*.
>
>>(1) from p.34, "Objects are instances of a particular class."
>
>
>>(4) from Appendix 1, p.432, "An instance is an object of a specific class."
>
>Yeah, he's just saying that an object == an instance of a class.
>Instance and Object are often used interchangeably.
>
>>Can anyone make sense of this?  Are two different meanings to 'object'
>>begin used, as for example in (1) compared to (4)?
>
>There is no difference.  Just two ways of saying the same thing.
>

Does anyone else see this as an instance :) of the classic situation
of a dictionary defining word A as "see B" and word B as "see A"?

It's poorly written.  Essentially, the book is defining the words
in terms of each other, so that it is not clear unless you're
familiar with the concepts what is being said.

Here's hoping that the other posts are clarifying things.


-- 
John Altinbay   -   altinbay@netcom.com   anon-1014@twwells.com
===============================================================
There's a spirit that guides me, a light that shines for me
My life is worth the living, I don't need to see the end.
