php7 支持通过 new class 来实例化一个匿名类，这可以用来替代一些“用后即焚”的完整类定义。 ~~~php <?php interface Logger { public function log(string $msg); } class Application { private $logger; public function getLogger(): Logger { return $this->logger; } public function setLogger(Logger $logger) { $this->logger = $logger; } } $app = new Application; $app->setLogger(new class implements Logger { public function log(string $msg) { echo $msg; } }); var_dump($app->getLogger()); ?> ~~~ 以上例程会输出： ~~~txt object(class@anonymous)#2 (0) { } ~~~