PHP OOP Bug

Anders Hellström

Monday, March 9. 2009

Posted by Anders Hellstrom in Lang:EN, PHP

Comments (0)
Trackbacks (0)

While working on a project this morning I discovered what appears to be a bug in PHP when dealing with objects and calling functions statically. I was calling a static function of a class from within an object of a different class. However, I had forgotten the name of the function I needed to call and ended up calling the wrong function. And even though the function I called wasn't declared as static I didn't get any error. Instead $this in the function ended up referring to the calling object.

Here's a short example:

class A {
private $variable;
public function foo() {
$this->variable = 'Hello B!';
}
}
class B {
public function bar() {
A::foo();
}
}
$myB = new B();
print_r($myB);
$myB->bar();
print_r($myB);

And the output:

B Object
(
)
B Object
(
[variable] => Hello B!
)

Update:
I've only tried this in version 5.2.6 so far. I suppose it might be the intended behavior but it seems rather odd to me. Though come to think of it, you don't get any errors when calling a non-static function statically from global scope when the function never use $this. In my opinion, these situations should cause a fatal error.

Trackbacks

Trackback specific URI for this entry

No Trackbacks

Comments

Display comments as (Linear | Threaded)

No comments

Add Comment

Name
Email
Homepage
In reply to
Comment	You can use [geshi lang=lang_name [,ln={y\|n}]][/geshi] tags to embed source code snippets. Enclosing asterisks marks text as bold (word), underscore are made via _word_. Standard emoticons like :-) and ;-) are converted to images. To prevent automated Bots from commentspamming, please enter the string you see in the image below in the appropriate input box. Your comment will only be submitted if the strings match. Please ensure that your browser supports and accepts cookies, or your comment cannot be verified correctly. Enter the string from the spam-prevention image above:
	Remember Information? Subscribe to this entry

Frontpage - Top level

Calendar

Quicksearch

Who's cnb anyway?

Anders Hellström, also known as cnb, is a Systems Engineer, web developer and PHP expert living in Uppsala, Sweden. Specializing in advanced highly available and fault tolerant hosting solutions using Linux, VMware and Cisco Networking he is currently employed by Rackfish AB. In his spare time he is also the Chairman of the Board at the local Linux User Group.