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From: Christoph Bussenius <busseniu@cip.physik.uni-muenchen.de>
To: Fabio Andres Miranda <fabiomiranda@racsa.co.cr>,
	linux-c-programming@vger.kernel.org
Subject: Re: Pointers to int
Date: Fri, 28 Oct 2005 18:05:30 +0200	[thread overview]
Message-ID: <20051028160530.GE6673@opaque.pepe> (raw)
In-Reply-To: <4362255E.90303@racsa.co.cr>

On Fri, Oct 28, 2005 at 07:19:26AM -0600, Fabio Andres Miranda wrote:
> Can anyone explain to the list how this pointers to int work:
>    int *p;
>    p = (int *)(array);
>    for (i = 0; i < arraysize - 1; i += 4)
>        *p++ = j - 8;
>    *p = 0x0;
> 
> P is defined as a pointer to a int. Then, it points to (the beginning ? 
> ) a char array.
> What is the result of perform the instruction: *p++; ?

As postincrement (++) has higher priority than dereference (*), p++ is
what will be evaluated first.  So p will be incremented by the size of
an integer (probably 4).  After that, p will point to the second integer
of the array, i. e. array[1].  Now you use * to access that very
location and store j-8 there.

HTH,
Christoph

-- 
``There's no dark side of the moon, really
Matter of fact, it's all dark''

--Pink Floyd

  reply	other threads:[~2005-10-28 16:05 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-10-28 13:19 Pointers to int Fabio Andres Miranda
2005-10-28 16:05 ` Christoph Bussenius [this message]
2005-10-28 16:09   ` Christoph Bussenius
2005-10-29 15:44 ` Glynn Clements

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