Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:9010
Return-Path: <jochem@iamjochem.com>
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Delivered-To: mailing list internals@lists.php.net
Received: (qmail 64281 invoked by uid 1010); 8 Apr 2004 18:06:33 -0000
Delivered-To: ezmlm-scan-internals@lists.php.net
Delivered-To: ezmlm-internals@lists.php.net
Received: (qmail 64252 invoked from network); 8 Apr 2004 18:06:33 -0000
Received: from unknown (HELO conan) (217.148.166.184)
  by pb1.pair.com with SMTP; 8 Apr 2004 18:06:33 -0000
Received: from [127.0.0.1] (helo=iamjochem.com)
	by conan with esmtp (Exim 4.30)
	id 1BBdv6-0001u8-NQ
	for internals@lists.php.net; Thu, 08 Apr 2004 20:06:32 +0200
Message-ID: <40759487.9040006@iamjochem.com>
Date: Thu, 08 Apr 2004 20:05:59 +0200
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5) Gecko/20031007
X-Accept-Language: en-us, en
MIME-Version: 1.0
To:  internals@lists.php.net
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
Subject: null / unset / isset ?
From: jochem@iamjochem.com (Jochem Maas)

consider this if you will:

<?

echo <<< ___THEEND
EXPECT:
isset(): true;
is_null(): true;

REALITY:
___THEEND;

$varIsSet = null;
var_dump( isset($varIsSet) );
var_dump( is_null($varIsSet) );

?>

I would have thought that having set the variable to something even if 
its 'nothing' would mean it is set in the current variable scope.

either that or it makes unset() redundant, no? and the PHP documentation
leaves me with the impression that is_null() works with 'set' variables 
(and would give an E_NOTICE if an unset variable is set)

is there a difference between null and unset()ing? does a variable that 
is null take up no memory (rather like variable that have never been 
defined or removed completely)

apologies if this is misplaced.

rgds,

Jochem