/*
 * T04n02.java -- Demonstration of Inheritance
 *
 * Unlike T04n01, this time SavingsAccount inherits from Account, so
 * all of Account's methods are now also SavingsAccount's methods.
 * In this case, inheritance is more appropriate than composition
 * because a SavingsAccount "is a" variety of Account.
 *
 * Note that the main program is the same in both examples.
 */

import java.io.*;

class Account 
{
    private int balance;

    public Account () { balance = 1; }

    public Account (int initialBalance) { balance = initialBalance; }

    public int fetchBalance() { return balance; }

    public void setBalance(int newBalance) { balance = newBalance; }
}

class SavingsAccount extends Account   // This is Java syntax for inheritance
{
    public SavingsAccount () {
        // Account's 0-argument constructor is invoked automatically
    }

    public SavingsAccount (int startingBalance) {
        super(startingBalance);        // or: setBalance(startingBalance)
    }

    public int getBalance () {
        return super.fetchBalance();   // inheritance makes "super." optional
        //return fetchBalance();         // also works -- try it!
    }

}

public class T04n02
{
    public static void main (String [] args) 
    {
        SavingsAccount nestEgg = new SavingsAccount();

        System.out.println("Your starting balance is $" + nestEgg.getBalance()
                         + ".");
        nestEgg.setBalance(5000);
        System.out.println("Your balance is now $" + nestEgg.getBalance()
                         + ".");
    }
}