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From: sarah@laticorp.UUCP (Sarah Groves Hobart)
Newsgroups: comp.unix.wizards
Subject: Re: have I found a bug in K&R?
Message-ID: <324@laticorp.UUCP>
Date: Tue, 13-Oct-87 15:17:55 EDT
Article-I.D.: laticorp.324
Posted: Tue Oct 13 15:17:55 1987
Date-Received: Fri, 16-Oct-87 01:34:59 EDT
References: <517@hubcap.UUCP> <321@laticorp.UUCP> <7608@steinmetz.steinmetz.UUCP>
Organization: LatiCorp, Inc., San Francisco
Lines: 34
Keywords: argv definition

In article <7608@steinmetz.steinmetz.UUCP>, stpeters@dawn.steinmetz (Dick St.Peters) writes:
> In article <321@laticorp.UUCP> sarah@laticorp.UUCP (Sarah Groves Hobart) writes:
> >Remember that the following declarations are equivalent:
> >
> >char s[];
> >
> >char *s;
> 
> Actually, they're not.  The difference is like that between a constant
> and a variable: you can change the value of s (the address it points
> to) if you declare it as a pointer [variable], but you can't if you
> declare it as an array [constant].  Consider what "&s" means in the
> two cases.
> 
> 
> 

Right.  An array name IS a constant, so something like:

   ptr = &array_name;

is illegal.  I was referring to their equivalence as formal parameters
in a function definition.  A function that has been passed an array name
can believe it has either an array or a pointer and work with it
accordingly.

It is, however, legal to pass a function something of the form &a[0], or
even &a[5].  This is useful if you only want to pass part of a larger
array.

Interested parties are referred to K&R pp. 94-96.

Sarah Groves Hobart
{ihnp4,amdahl,sun}!ptsfa!laticorp!sarah