call a static method inside a class?
Let's assume this is your class:
class Test
{
private $baz = 1;
public function foo() { ... }
public function bar()
{
printf("baz = %d\n", $this->baz);
}
public static function staticMethod() { echo "static method\n"; }
}
From within the foo()
method, let's look at the different options:
$this->staticMethod();
So that calls staticMethod()
as an instance method, right? It does not. This is because the method is declared as public static
the interpreter will call it as a static method, so it will work as expected. It could be argued that doing so makes it less obvious from the code that a static method call is taking place.
$this::staticMethod();
Since PHP 5.3 you can use $var::method()
to mean <class-of-$var>::
; this is quite convenient, though the above use-case is still quite unconventional. So that brings us to the most common way of calling a static method:
self::staticMethod();
Now, before you start thinking that the ::
is the static call operator, let me give you another example:
self::bar();
This will print baz = 1
, which means that $this->bar()
and self::bar()
do exactly the same thing; that's because ::
is just a scope resolution operator. It's there to make parent::
, self::
and static::
work and give you access to static variables; how a method is called depends on its signature and how the caller was called.
To see all of this in action, see this 3v4l.org output.
self::staticMethod();
More information about the Static keyword.