Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!mcvax!cernvax!ethz!marti
From: marti@ethz.UUCP (Robert Marti)
Newsgroups: comp.lang.c++
Subject: Re: C++ and other OOP Languages
Keywords: C++, OOPS
Message-ID: <823@ethz.UUCP>
Date: 20 Apr 89 12:21:27 GMT
Organization: ETH Zuerich
Lines: 26

Some previous articles discussed the "object-orientedness" (what a
word!) of C++, Objective C and various other languages.  Let me add
me 2 cents worth, even though I usually regret posting my opinions
to USENET afterwards ... :-)

Today, most people can probably live with the following "definiton":
(We'll soon hear from those who can't :-)

A language is OO if
1) it supports data encapsulation (information hiding, abstract data types),
2) it supports inheritance (subclassing, extensible record types, ... )
   and
3) it supports determination of the procedure body to be executed at the
   time of the actual procedure call (message passing, virtual functions).

Using this definiton, C++, Objective-C, Smalltalk, Lisp+CLOS, Eiffel,
Modula-3, and Object-Pascal are all OO, since they fulfill all of the
above criteria.  Oberon only supports (1) and (2) directly, and is not
fully OO as a result.  Modula-2 and Ada (TM of somebody or other) only
support (1) and are definitely not OO.

-- 
Robert Marti                      Phone:      +41 1 256 52 36
Institut fur Informationssysteme
ETH-Zentrum                       CSNET/ARPA: marti%inf.ethz.ch@relay.cs.net
CH-8092 Zurich, Switzerland       UUCP:       ...uunet!mcvax!ethz!marti