Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!unmvax!nmtsun!kelly
From: kelly@nmtsun.nmt.edu (Sean Kelly)
Newsgroups: comp.lang.c
Subject: Another silly question
Message-ID: <2459@nmtsun.nmt.edu>
Date: 26 Apr 89 22:57:40 GMT
References: pointer array reference access element
Reply-To: kelly@titan.nmt.edu (Sean Kelly)
Organization: New Mexico Tech, Socorro NM
Lines: 32


My CS instructor and I disagree about a certain moot point.  I have a text
book which says that

	*(a + i)	and	a[i]

are equivalent, given an array a, and int index i ... each gives the
value stored in a[i].  But he says that

	*(a + i)

is non-standard and would not expect it do go far on all _real_ C compilers
(_real_ meaning those compilers that are somewhat devoted to K & R or ANSI).
He expects that many compilers would instead add the value of i to the
pointer a, and then reference the item stored there.  I say that the
compiler's smart enough to realize what we're trying to achieve, and
won't do something like

	* (char *) ( (int) a + i )

which he thinks it will probably do on most machines.  It doesn't on our
Suns nor our VAX.

I don't have a copy of K&R's book, first or new edition, just _Programming_
_in_C_ by S. Kochan, which seems pretty valid.

What do you think?

--
Sean Kelly                    I'm not a number, I am a free man!
kelly@nmtsun.nmt.edu          --The Prisoner
--