Online PHP editor | output for hkTDp

<?php readonly class Email { public function __construct(public string $emailString){} public function __toString() {return trim($this->emailString);} } readonly class ValidEmail extends Email {} function validateEmail(Email $email): ValidEmail {return new ValidEmail($email);} function saveToDatabase(ValidEmail $email) {return 'Saved succesfully';} $email = new Email('vasya@pupkin.com'); $validatedEmail = validateEmail($email); var_dump(saveToDatabase($validatedEmail)); var_dump(saveToDatabase($email));