Comments on: Dynamic Properties in PHP and StdClass

By: Rob’s Blog » Blog Archive » MySQLi vs PDO

Rob’s Blog » Blog Archive » MySQLi vs PDO — Tue, 21 Jul 2009 12:24:41 +0000

[...] Kris Jordan thinks that using __get and __set is around 30 times slower than using dynamic properties on StdClass. [...]

By: William

William — Fri, 10 Jul 2009 04:16:39 +0000

If you want to set multiple properties on a single line, you can do:

$object = (object)array(’key’ => ‘value’, ‘key2′ => ‘value2′);

The object created will be an stdClass instance.

By: m rahman

m rahman — Sat, 09 May 2009 05:51:25 +0000

Sometimes you need declaring objects on the fly just to hold abstract members, say for packing. To use $object = new foo(); you should have declared class foo{}, while you can just object=new stdclass;

By: ian

ian — Sat, 25 Apr 2009 01:17:26 +0000

had too google far & wide to find your piece. any idea why this isn’t documented in php.net? if it’s a feature, it should be documented, but if not, it’s a bug and ought to be fixed. it certainly gives the lie to the often-repeated advice to look it up in the php documentation.

By: Web development

Web development — Mon, 26 Jan 2009 22:54:55 +0000

class foo {};
$object = new foo();

try above

By: Kris

Kris — Thu, 27 Nov 2008 23:15:26 +0000

@Duke, @Wayne – Thanks for the heads up. I’ve corrected the post. Amazing the range of things PHP doesn’t make obvious in the official documentation. I’ve been using __get and __set in simple dynamic properties cases for years.

@Scott – StdClass is neat and nebulous. There really isn’t much about it on the net. It has been claimed to be the base class for all other classes in PHP but the following code bit returns false:

echo $b instanceof stdclass ? 'yes' : 'no'; // prints 'no'

By: duke

duke — Thu, 27 Nov 2008 19:35:09 +0000

Instead of :
class DynamicProperties extends StdClass { }
$object = new DynamicProperties;

You can do just:

class foo {};
$object = new foo();

and the rest of your code still works. No need to extend stdClass at all.

By: Scott

Scott — Thu, 27 Nov 2008 19:30:41 +0000

this is great, I didn’t know about stdClass. Where did you find the docs? the only mention I can find on php.net is “The name stdClass is used internally by Zend and is reserved. You cannot have a class named stdClass in PHP.”

By: Wayne

Wayne — Thu, 27 Nov 2008 18:26:06 +0000

Dynamic instance properties can be set on any class irregardless of whether or not they extend from stdClass. Declaring properties is entirely optional in PHP and always has been.

Try your BestDynamicProperties example without extending from stdClass and you’ll see that you get exactly the same result. Now try adding properties to any other PHP class and you’ll notice that works as well. stdClass is just an empty class, it has no special abilities.

If you don’t want dynamic properties on your classes (I usually don’t to cut down on typos going unnoticed), you can define the __set() magic method to throw an exception.