In the later PHP version `self::staticMethod();` also will not work. It will throw the strict standard error.
In this case, we can create object of same class and call by object
here is the example
class Foo { public function fun1() { echo 'non-static'; } public static function fun2() { echo (new self)->fun1(); } }

> Here is an example of correct usage of $this and self for non-static > and static member variables:
<?php class X { private $non_static_member = 1; private static $static_member = 2; function __construct() { echo $this->non_static_member . ' ' . self::$static_member; } } new X(); ?>