<?phpclass Account { public $balance; function __construct( $balance ) { $this->balance = $balance; }}class Person { private $name; private $age; private $id; public $account; function __construct( $name, $age, Account $account ) { $this->name = $name; $this->age = $age; $this->account = $account; } function setId( $id ) { $this->id = $id; } function __clone() { $this->id = 0; }}$person = new Person("Joe", 35, new Account( 2000 ) );$person->setId( 111 );$person2 = clone $person;$person->account->balance += 110;print $person2->account->balance;?>