无法从对象PHP获取属性值

if (property_exists($object, 'propertyName')) {
    echo $object->propertyName;
} else {
    echo 'Property does not exist.';
}

class MyClass {
    private $propertyName;

    public function getPropertyName() {
        return $this->propertyName;
    }
}

$object = new MyClass();
echo $object->getPropertyName();

if ($object instanceof MyClass) {
    echo $object->propertyName;
} else {
    echo 'Object is not an instance of MyClass.';
}

class MyClass {
    private $propertyName;

    public function __get($name) {
        if ($name == 'propertyName') {
            return $this->propertyName;
        }
    }
}

$object = new MyClass();
echo $object->propertyName;

class User {
    private $name;
    private $email;

    public function __construct($name, $email) {
        $this->name = $name;
        $this->email = $email;
    }

    public function getName() {
        return $this->name;
    }

    public function getEmail() {
        return $this->email;
    }
}

$user = new User('John Doe', 'john@example.com');
echo $user->getName(); // 输出: John Doe
echo $user->getEmail(); // 输出: john@example.com