Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!xanth!kremer
From: kremer@cs.odu.edu (Lloyd Kremer)
Newsgroups: comp.lang.c
Subject: Re: comma operator:  keep away?
Summary: Sometimes it's handy
Message-ID: <8611@xanth.cs.odu.edu>
Date: 24 Apr 89 16:00:55 GMT
References: <19913@iuvax.cs.indiana.edu>
Organization: Old Dominion University, Norfolk, Va.
Lines: 35



In article <19913@iuvax.cs.indiana.edu> bobmon@iuvax.cs.indiana.edu (RAMontante)
writes:
>Is there a circumstance in which the comma operator is required, where
>the compound statement cannot be broken into multiple statements?

Perhaps not required, but convenient nevertheless.

I often use it for loop tests using functions that "get" information but
do not "return" the information they get.  For example:

	extern double frexp();
	double f[SIZE];
	int i, exp;

	...
	while(frexp(f[i++], &exp), exp < 10)
		statement;
	...

Another example would be:

	char c;

	while(read( ..., &c, 1), c != '\n')

assuming EOF detection is not needed for this read() (horrible assumption,
I know).

-- 
					Lloyd Kremer
					Brooks Financial Systems
					...!uunet!xanth!brooks!lloyd
					Have terminal...will hack!