Newsgroups: php.internals Path: news.php.net Xref: news.php.net php.internals:93542 Return-Path: Mailing-List: contact internals-help@lists.php.net; run by ezmlm Delivered-To: mailing list internals@lists.php.net Received: (qmail 61866 invoked from network); 25 May 2016 22:01:10 -0000 Received: from unknown (HELO lists.php.net) (127.0.0.1) by localhost with SMTP; 25 May 2016 22:01:10 -0000 Authentication-Results: pb1.pair.com smtp.mail=lester@lsces.co.uk; spf=permerror; sender-id=unknown Authentication-Results: pb1.pair.com header.from=lester@lsces.co.uk; sender-id=unknown Received-SPF: error (pb1.pair.com: domain lsces.co.uk from 217.147.176.214 cause and error) X-PHP-List-Original-Sender: lester@lsces.co.uk X-Host-Fingerprint: 217.147.176.214 mail4-2.serversure.net Linux 2.6 Received: from [217.147.176.214] ([217.147.176.214:52503] helo=mail4.serversure.net) by pb1.pair.com (ecelerity 2.1.1.9-wez r(12769M)) with ESMTP id 54/30-14311-3A026475 for ; Wed, 25 May 2016 18:01:09 -0400 Received: (qmail 20886 invoked by uid 89); 25 May 2016 22:01:04 -0000 Received: by simscan 1.3.1 ppid: 20863, pid: 20877, t: 1.2667s scanners: attach: 1.3.1 clamav: 0.96/m:52/d:10677 Received: from unknown (HELO ?10.0.0.7?) (lester@rainbowdigitalmedia.org.uk@81.138.11.136) by mail4.serversure.net with ESMTPA; 25 May 2016 22:01:02 -0000 To: internals@lists.php.net References: <7B.12.14311.F79C5475@pb1.pair.com> <1b12b09f-f190-dca0-51d9-468e9c571268@fleshgrinder.com> <4ec823c6-b039-fc91-7c78-60d67719cd81@gmail.com> <00482771-3a07-06cf-ee8d-cd83a301c7e7@fleshgrinder.com> Message-ID: <5746209D.4030205@lsces.co.uk> Date: Wed, 25 May 2016 23:01:01 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0 MIME-Version: 1.0 In-Reply-To: <00482771-3a07-06cf-ee8d-cd83a301c7e7@fleshgrinder.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [PHP-DEV] [RFC][Vote] Typed Properties From: lester@lsces.co.uk (Lester Caine) On 25/05/16 22:42, Fleshgrinder wrote: > It is not the same as null, very similar, but definitely not the same. > Think of it in DB terms: > > | table | > | ----- | > | id | > > SELECT name FROM table; > > That's not null, it's not defined (undefined, unset, ...). In other > words, null is a value and undefined/unset a state. If no field 'name' exists then you get an error. If no valid record is found then name will be populated with 'NULL' if you try and read the returned record ... unless the 'noofrec' variable is accessed first and establishes that '0' records were returned. If you are reading a set of fields for which some have no matching values then these are returned as 'NULL' while the rest will be populated. NULL is ALWAYS a 'state' meaning that this field is undefined or more accurately unset. -- Lester Caine - G8HFL ----------------------------- Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk Rainbow Digital Media - http://rainbowdigitalmedia.co.uk