class Base { protected static function whoami() { echo "Base "; } public static function whoareyou() { static::whoami(); } } class A extends Base { public static function test() { Base::whoareyou(); self::whoareyou(); parent::whoareyou(); A::whoareyou(); static::whoareyou(); } public static function whoami() { echo "A "; } } class B extends A { public static function whoami() { echo "B "; } } B::test();