PHP多例模式探讨

abstract class Multiton { /** by http://www.phpddt.com */ private static $instances = array(); public static function getInstance() {
        $key = get_called_class() . serialize(func_get_args()); if (!isset(self::$instances[$key])) {
            $rc = new ReflectionClass(get_called_class());
            self::$instances[$key] = $rc->newInstanceArgs(func_get_args());
        } return self::$instances[$key];
    }
}
  class Hello extends Multiton { public function __construct($string = 'World') {
        echo "Hello $string\n";
    }
}
  class GoodBye extends Multiton { public function __construct($string = 'my', $string2 = 'darling') {
        echo "Goodbye $string $string2\n";
    }
}
 
$a = Hello::getInstance('World');
$b = Hello::getInstance('bob'); // $a !== $b  
$c = Hello::getInstance('World'); // $a === $c  
$d = GoodBye::getInstance();
$e = GoodBye::getInstance(); // $d === $e  
$f = GoodBye::getInstance('your'); // $d !== $f  ?>