<?phpclass example{    public static $pa;    public $pb;    public function __construct(){        $this->pb = ++self::$pa;    }        public function __clone(){        $this->pb = 'no zuo no die';    }}$a = new example;$b = new example;$c = clone $b;$b->pb = 'I Love You So Much!';echo $a->pb;echo '<hr/>';echo $b->pb;echo '<hr/>';echo $c->pb;echo '<hr/>';echo $b->pb;?>