Superclass的构造函数是在PHP中的子构造函数中运行的吗？

class Superclass {
    public function __construct() {
        echo "Superclass constructor called.";
    }
}

class Subclass extends Superclass {
    public function __construct() {
        parent::__construct();
        echo "Subclass constructor called.";
    }
}

$subclass = new Subclass();