Class method? Instance method? It doesn't matter to PHP
∞Update: This has been discussed for PHP6. A little late, but I guess better than never.
I made a mistake while I was coding, for shame! Anyway this particular mistake was that I invoked a class method on the wrong class. The funny part was that this method was an instance method in the class which I typed by mistake. In the error log I saw something like "Invalid use of $this in class function."
I knew for a fact I hadn't used $this in a class method, so it was kind of a confusing error. I went to the file in question and found out that it was calling an instance method as a class method. Now that is some crazy shit.
I would fully expect the PHP parser to give me an error like "No class method [foo] in class [blah]", rather than try and execute it as a class method. The syntax is completely different; you use :: to call a class method and -> to call an instance method. And you use the name of a class when you call a class method.
This code:
class Foo {
public static function static_fun()
{
return "This is a class method!\n";
}
public function not_static()
{
return "This is an instance method!\n";
}
}
echo '<pre>';
echo "From Foo:\n";
echo Foo::static_fun();
echo Foo::not_static();
echo "\n";
echo "From \$foo = new Foo():\n";
$foo = new Foo();
echo $foo->static_fun();
echo $foo->not_static();
echo '</pre>';
Produces:
From Foo:
This is a class method!
This is an instance method!
From $foo = new Foo():
This is a class method!
This is an instance method!
What the fuck?! http://www.php.net/manual/en/language.oop5.static.php is lying to everyone.