44 The Value Object Pattern

* @return void

*/ public function passGo($player) {

$player->collect($this->go_amount); }

}

So far, the Monopoly class is very minimal. The constructor creates $go_amount, an instance of the Dollar Value Object class, set to $200. $go_amount is used by passGo(), which takes a Player as an argument and tells the Player to collect() $200.

Player should be next. The Monopoly class calls a Player::collect() method with one argu-ment, a Dollar, to add that Dollar amount to the player’s cash balance. In addition to that method, let’s add the method Player::getBalance() to access a player’s cash reserve current to validate that the Player and Monopoly objects are working,

class Player { protected $name; protected $savings; /**

* constructor

* set name and initial balance

* @param string $name the players name

* @return void */

public function __construct($name) {

$this->name = $name;

$this->savings = new Dollar(1500); } /**

* receive a payment

* @param Dollar $amount the amount received

* @return void */

public function collect($amount) {

$this->savings = $this->savings->add($amount); }

* return player balance

* @return float */

public function getBalance() {

return $this->savings->getAmount(); }

}



	44 The Value Object Pattern

	* @return void */ public function passGo($player) { $player->collect($this->go_amount); }

	}

	So far, the Monopoly class is very minimal. The constructor creates $go_amount, an instance of the Dollar Value Object class, set to $200. $go_amount is used by passGo(), which takes a Player as an argument and tells the Player to collect() $200. Player should be next. The Monopoly class calls a Player::collect() method with one argu-ment, a Dollar, to add that Dollar amount to the player’s cash balance. In addition to that method, let’s add the method Player::getBalance() to access a player’s cash reserve current to validate that the Player and Monopoly objects are working,

	class Player { protected $name; protected $savings; /** * constructor * set name and initial balance * @param string $name the players name * @return void / public function __construct($name) { $this->name = $name; $this->savings = new Dollar(1500); } /* * receive a payment * @param Dollar $amount the amount received * @return void / public function collect($amount) { $this->savings = $this->savings->add($amount); } return player balance * @return float */ public function getBalance() { return $this->savings->getAmount(); }

	}