ch04/cashregister/CashRegisterTester.java
 /**
 This class tests the CashRegister class.
 */
 public class CashRegisterTester
 {
public static void main(String[] args)
 {
 CashRegister register = new CashRegister();

 register.recordPurchase(0.75);
 register.recordPurchase(1.50);
 register.enterPayment(2, 0, 5, 0, 0);
 System.out.print(Change: );
 System.out.println(register.giveChange());
 System.out.println(Expected: 0.25);

 register.recordPurchase(2.25);
 register.recordPurchase(19.25);
 register.enterPayment(23, 2, 0, 0, 0);
 System.out.print(Change:);
 System.out.println(register.giveChange());
System.out.println(Expected: 2.0);
 }
 }