Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:37378
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain omegavortex.net from 207.210.105.196 cause and error)
Message-ID: <4818B531.7040505@omegavortex.net>
Date: Wed, 30 Apr 2008 13:06:41 -0500
Organization: Omega Vortex Corporation
User-Agent: Thunderbird 2.0.0.12 (Windows/20080213)
MIME-Version: 1.0
To: Nathan Nobbe <quickshiftin@gmail.com>
CC: internals@lists.php.net
References: <7dd2dc0b0804300921y4d87fa25k3530cb864367aa24@mail.gmail.com>
In-Reply-To: <7dd2dc0b0804300921y4d87fa25k3530cb864367aa24@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] why interfaces ?
From: jeremy@omegavortex.net (Jeremy Privett)

Nathan Nobbe wrote:
> all,
>
> in recent weeks there has been a lot of arguing about what interfaces are,
> arent (on php-general and now on the internals list as well) etc. etc.
>
> i am quite curious, why interfaces were added to the language in the first
> place.  note, i am not criticizing them, i am overjoyed that the language
> has them, however i am curious about the history.  is this something php
> borrowed from java?  does it have anything to do with 'entirely virtual
> classes' in c++ ?  i think that the history behind the addition of
> interfaces to php, would shed a lot of light on their intended purpose for
> use by php developers.
>
> thanks,
>
> -nathan
>
>   

"Interfaces" exist in different OO-enabled languages. PHP strengthened 
its object model in PHP 5, and thus the introduction of interfaces. I'm 
pretty sure the intended purpose of interfaces was just like pretty much 
every other language. You implement interfaces in order to provide a 
consistent API. As long as class A implements interface B, I can be for 
certain that it's going to contain methods C and D. Interfaces also give 
you the ability to "type hint" against them, requiring objects that 
implement that interface, thus ensuring you know what methods are on 
that object.

Interfaces are a very powerful feature, when implemented properly.

-- 
Jeremy Privett
C.E.O. & C.S.A.
Omega Vortex Corporation

http://www.omegavortex.net

Please note: This message has been sent with information that could be confidential and meant only for the intended recipient. If you are not the intended recipient, please delete all copies and inform us of the error as soon as possible. Thank you for your cooperation.