Understanding class definitions - Objects First with Java: A Practical Introduction Using BlueJ - page 40

Code 2.8
A more sophisticated
TicketMachine

/**
* TicketMachine models a ticket machine that issues
* flat-fare tickets.
* The price of a ticket is specified via the constructor.
* Instances will check to ensure that a user only enters
* sensible amounts of money, and will only print a ticket
* if enough money has been input.
* @author David J. Barnes and Michael Kölling
* @version 2011.07.31
*/
public class TicketMachine
{
// The price of a ticket from this machine.
private int price;
// The amount of money entered by a customer so far.
private int balance;
// The total amount of money collected by this machine.
private int total;

/**
* Create a machine that issues tickets of the given price.
*/
public TicketMachine( int cost)
{

price = cost;
balance = 0;
total = 0;

}

/**
* Return the price of a ticket.
*/
public int getPrice()
{

return price;

}

/**
* Return the amount of money already inserted for the
* next ticket.
*/
public int getBalance()
{

return balance;

}