instance = ++self::$instances; } public function __clone() { $this->instance = ++self::$instances; } } $test = new my_class3; $test2 = clone $test; echo $test->instance; echo "
\n"; echo $test2->instance; ?>]]> Note that we are not overriding the cloning with our __clone() method. Think of it as a fixup that is called after the actual copy has been done.