PHP7 匿名类

PHP 7 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
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());
?>

以上程序会输出：

object(class@anonymous)#2 (0) {
}