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From: chris@mimsy.umd.edu (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: Odd trivia question involving && and ,
Keywords: && , if
Message-ID: <24137@mimsy.umd.edu>
Date: 3 May 90 06:13:19 GMT
References: <1990May2.181709.8988@dasys1.uucp>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 33

In article <1990May2.181709.8988@dasys1.uucp> aj-mberg@dasys1.uucp
(Micha Berger) writes:
>Do these peices of source code produce significantly different object
>code?

The answer to the question you asked is `yes', but the answer to the
question you probably meant to ask is `no':

>	E1 &&
>		E2,
>		E3;

(vs)

>	if (E1) {
>		E2;
>		E3;
>	}

Since `&&' binds tighter than `,', the first fragment is equivalent to

	if (E1) E2;
	E3;

If you change the first fragment to

	E1 && (E2, E3);

then the answer is `no, not unless you try to get the value of the
exression'---at least, not in any decent compiler.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris