Path: utzoo!utgpu!water!watmath!clyde!rutgers!sunybcs!boulder!tramp!swarbric
From: swarbric@tramp.Colorado.EDU (SWARBRICK FRANCIS JOHN)
Newsgroups: comp.lang.c
Subject: comma operator
Message-ID: <3819@sigi.Colorado.EDU>
Date: 14 Jan 88 01:48:26 GMT
Sender: news@sigi.Colorado.EDU
Reply-To: swarbric@tramp.Colorado.EDU (SWARBRICK FRANCIS JOHN)
Organization: University of Colorado, Boulder
Lines: 34

I'd never used the comma operator before (except in for() statements), so
today I thought I would see what it does.  I did the following program.

#include <stdio.h>

main()
{
 int i=0,j;

 /* assignment code goes here */
 printf("%d %d\n",i,j);
}

in place of the comment up there I put the following different things...

1) j = i,i++;
2) j = i,++i;
3) j = i;
   i++;
4) j = i;
   ++i;
5) j = i++;

All five gave the answer "1 0," and (using Turbo C) they all generate the
same amount of code (OBJ = 223, EXE = 5408).  I assume by this that they
generated the same exact code, though I was too lazy to check.  So, what is
the advantage of using the comma operator other than to squeeze everything
on to one line?

------------------------------------------------------------------
Frank Swarbrick                   |  "Ignorance and prejudice --
swarbric@tramp.UUCP               |   And fear walk and in hand."
swarbric@tramp.Colorado.EDU       |                         --RUSH
...!{hao|nbires}!boulder!tramp!swarbric