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From: tomkwong@banana.ucsb.edu (Thomas K. Kwong)
Newsgroups: comp.lang.c
Subject: Re: Array question
Message-ID: <9304@hub.ucsb.edu>
Date: 21 Feb 91 18:53:03 GMT
References: <EbhAAgG00WBNM2PIt_@andrew.cmu.edu>
Sender: news@hub.ucsb.edu
Reply-To: tomkwong@banana.UUCP (Thomas K. Kwong)
Organization: University of California, Santa Barbara
Lines: 34

In article <EbhAAgG00WBNM2PIt_@andrew.cmu.edu> rg2c+@andrew.cmu.edu (Robert Nelson Gasch) writes:
>
>    int *this_ptr;
>    this_ptr [0] = 1;
>    this_ptr [1] = 2;
>    . . . 
>    this_ptr [9] = 10;
>
>This works fine, but I really don't know why?? It seems you're using
>memory to store an array which was never really allocated. If anybody
>could briefly explain what exactly happens when you do this, I'd be
>greatly abliged as at this point I'm mystified. 

An array subscript is really a shorthand of a pointer notation:
	a[i]   is exactly the same as    *(a+i)
This conversion is done in compile time, so what you're doing is just
using the space allocated in previous malloc() statement.

-Thomas.

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