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From: emz@bjcong.bj.co.uk (ED ZIETARSKI)
Newsgroups: comp.lang.c
Subject: Re: extern
Summary: Yes, it is an error to include array size in extern declaration
Message-ID: <910@bjcong.bj.co.uk>
Date: 28 Jun 90 14:01:31 GMT
References: <111254@linus.mitre.org>
Organization: Boldon James Limited (Congleton, UK)
Lines: 23

In article <111254@linus.mitre.org>, cookson@helios.mitre.org (Dean Cookson) writes:
> I know that if you have an extern that is an array, you don't have to use
> the size of the array in the extern declaration, you only need it in
> the original declaration.  But is it an error to include it in the
> extern declaration??
> 
> ie:
> file1.c
> int	myarray[10];
> 
> file2.c
> extern int	myarray[10];
I would say it is an error because if you or someone else changes the array size
at a later stage, (s)he would have to also know/remember that the external
declaration needs changing. Even if you use a #define for the array size, you
could still have the situation arising of someone deciding to use a *different*
preprocessor definition name. The compiler cannot pick up differences in array
sizes in a set of objects and neither can the linker (as far as I know !)
---
Ed Zietarski, Boldon James Limited, Congleton, CHESHIRE CW12 1JN, UK.
emz@bj.co.uk (UK only)
emz@boldon-james-limited.co.uk (Internet)
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