Classes can define types. Here is a toy CashRegister class.

• It has no main method, so it can't be executed by itself.
• It has both static and non-static data members.
• It has a Constructor
• It has non-static methods.

    1   
    2   public class CashRegister
    3   {
    4     public static final double QUARTER = 0.25;
    5     public static final double DIME = 0.10;
    6     public static final double NICKEL = 0.05;
    7     public static final double PENNY = 0.01;
    8   
    9     private double purchase;
   10     private double payment;
   11   
   12     public CashRegister() {
   13       purchase = 0;
   14       payment = 0;
   15     }
   16   
   17     public void recordPurchase(double amount) {
   18       purchase += amount;
   19     }
   20   
   21     public void enterPayment(int dollars, int quarters, int dimes,
   22                              int nickels, int pennies) {
   23       payment = ...;
   24   
   25     }
   26   
   27     public double giveChange() {
   28       double change = payment - purchase;
   29       purchase = 0;
   30       payment = 0;
   31       return change;
   32     }
   33     
   34   }