Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!taumet!steve
From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.lang.c
Subject: Re: When do you use const
Keywords: const, #define, C
Message-ID: <578@taumet.com>
Date: 4 Feb 91 16:24:12 GMT
References: <1220@tredysvr.Tredydev.Unisys.COM>
Organization: Taumetric Corporation, San Diego
Lines: 13

paul@tredysvr.Tredydev.Unisys.COM (Paul Siu) writes:

>However, what is the advantage of using const over #define?  Why was the
>reason for its addition to ANSI C.

A lot of good answers were posted to this question, but I didn't see any
mention of scoping.  Macros are not scoped.  They exist from the textual
point of declaration to the end of the compilation, unless #undef'd.  So
an innocent #define buried somewhere in the program (inside a function,
or in a nested include file) can unintentionally affect later code.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com