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+--- Thread: A fairly dumb question... (/showthread.php?tid=6538)
A fairly dumb question... - El Forum - 03-03-2008
[eluser]Lovecannon[/eluser]
This has always confused me, what is the main difference in using -> and :: for calling methods of a class? Is :: only for static methods? and can static methods be called via ->? I feel dumb for asking this question..
A fairly dumb question... - El Forum - 03-03-2008
[eluser]Hyra[/eluser]
The main difference, if not the only one, is that you use the double colon for static members, and the arrow for members
Static Member
Code:
class Foo
{
public static $my_static = 'foo';
public function staticValue() {
return self::$my_static;
}
}
class Bar extends Foo
{
public function fooStatic() {
return parent::$my_static;
}
}
print Foo::$my_static . "\n";
$foo = new Foo();
print $foo->staticValue() . "\n";
print $foo->my_static . "\n"; // Undefined "Property" my_static
// $foo::my_static is not possible
print Bar::$my_static . "\n";
$bar = new Bar();
print $bar->fooStatic() . "\n";Static method
Code:
class Foo {
public static function aStaticMethod() {
// ...
}
}
Foo::aStaticMethod();So .. :: can only be used for static (non-changing) methods/members
A fairly dumb question... - El Forum - 03-03-2008
[eluser]Negligence[/eluser]
Basically, yes.
--> is used for objects (instantiations of a class), while :: accesses a classes' methods directly without the need for an object. You can use :: to access non-static methods, but static methods must be called with ::.
I would recommend reading the OOP section in the PHP documentation. This is pretty basic knowledge you should have.
A fairly dumb question... - El Forum - 03-03-2008
[eluser]Lovecannon[/eluser]
I learned PHP 4 years ago on PHP4, I never really used static variables or methods in PHP, even when PHP5 came out.