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To: Johannes Mueller <johannes_m@gmx.net>
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Date: Sat, 19 Dec 2009 01:52:51 +0100
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Subject: Re: [PHP-DEV] is_a() versus instanceof
From: johannes@php.net (Johannes =?ISO-8859-1?Q?Schl=FCter?=)

On Sat, 2009-12-19 at 01:42 +0100, Johannes Mueller wrote:
> if($foo instanceof bar){
> ..
> }
> // runs without any notification

instanceof is a language construct expecting a class identifier.
It doesn't complain about on-existing classes as it would need to
trigger the __autoloader which might be way too much.

> and
> 
> if(is_a($foo, bar)){
> ..
> }
> // runs with an undefined constant bar notification

is_a() is a function expecting a string. And this warning is unrelated
to the fact that the class "bar" doesn't exist, but due to the way PHP
treats undefined constants.

Behavior is expected,
johannes