Online PHP editor | refs for CX7fI

<?php class ValueObject implements JsonSerializable { protected $value; public function jsonSerialize() { return $this->value; } } class Email extends ValueObject { public function __construct(string $value) { $email = filter_var($value, FILTER_VALIDATE_EMAIL); if (false === $email) { throw new Exception('Email is invalid.'); } $this->value = $email; } } class Age extends ValueObject { public function __construct(int $value) { if ($value > 150) { throw new Exception('Age must be less than 150.'); } $this->value = $value; } } class User implements JsonSerializable { private $email; private $age; public function __construct(Email $email) { $this->email = $email; } public function setAge(Age $age) { $this->age = $age; } public function jsonSerialize() { return ['email' => $this->email, 'age' => $this->age]; } } $email = new Email('opexus@gmail.com'); $age = new Age(23); $user = new User($email); $user->setAge($age); echo json_encode($user);