Online PHP editor | output for WksJS

<?php readonly class ValidAge { private const MINIMUM_AGE = 10; private function __construct(public int $age) {} public static function createFromInt(int $age): self|NotValidAge { if (self::MINIMUM_AGE >= $age) { return new NotValidAge($age, 'Too old'); } return new self($age); } } readonly class NotValidAge { public function __construct( public int $age, public string $error ) {} } class ValidateAge { public function __invoke(int $age): ValidAge|NotValidAge { return ValidAge::createFromInt($age); } } class User { public function __construct( public int $id, public ValidAge $age ) {} } $rawAge = 33; $age = (new ValidateAge)($rawAge); $user = new User(1, $age); var_dump($user); $wrongAge = 8; $notValidAge = (new ValidateAge)($wrongAge); $anotherUser = new User(1, $notValidAge); var_dump($anotherUser);