Path: utzoo!attcan!uunet!samsung!munnari.oz.au!metro!cluster!nuts!cc.nu.oz.au!v8902477
From: v8902477@cc.nu.oz.au
Newsgroups: comp.lang.c
Subject: 2D array question
Message-ID: <3336.268f44b2@cc.nu.oz.au>
Date: 2 Jul 90 02:57:22 GMT
Organization: University of Newcastle
Lines: 28


	Hello,  could somebody please help me with the following? I'm attempting
to create a two dimensional array at run time using calloc.  The array is an
array of structures like this :

	struct a {
		int a1, a2, a3;
	};

And I'm using :

	array = (struct a *) calloc(xdim*ydim, sizeof(struct a));

to allocate space for the array.  xdim and ydim are the dimensions.  I believe
this correct.  It seems to work.  The problem came when I attempted to assign a
value to an element in the array.  I tried it this way :

	*((array+x+y*ydim).a1) = value;

Am I correct with this?  If array is a pointer it's okay to add integers to it
and use the sum as a pointer, is it not?  I get an error stating that .a1 is not
a valid lvalue.  Should I be using -> somewhere?

Help please!

Bernard.

Sorry if this has been asked before.