public class LoudToy
{

   public void makeNoise()
   {
       System.out.println("Generic sound!");
   }
}

public class ToyRobot extends LoudToy
{

    public void makeNoise()
    {
        System.out.println("BEEP BEEP!");
    }

    public void recharge()
    {
        System.out.println("Recharging...   Fully charged!");
    }
}

public class ToySheep extends LoudToy
{

    public void makeNoise()
    {
        System.out.println("Baah. Baah.");
    }
   
}



/**
 * Simple examples of polymorphism and dynamic binding. 
 * 
 * @author Nathan Sprague
 *
 */
public class ToyMain
{

    public static void main(String args[])
    {
        badCastingExample();
    }

    public static void nonPolymorphism()
    {
        ToyRobot robot;
        robot = new ToyRobot();
        robot.makeNoise();
        robot.recharge();
    }

    public static void polymorphismAndDynamicBinding()
    {
        LoudToy toy;
        toy = new ToySheep();
        toy.makeNoise();    
        toy = new ToyRobot();
        toy.makeNoise();
        //toy.recharge(); // Won't compile, even though toy contains a ToyRobot.
    }
    
    public static void castingExample()
    {
        LoudToy toy;
        toy = new ToyRobot();
        toy.makeNoise();

	// This cast is OK.  toy does contain a ToyRobot.	
        ToyRobot robot = (ToyRobot)toy;
        robot.recharge();
    }
    
    public static void badCastingExample()
    {
        LoudToy toy;
        toy = new ToySheep();
        toy.makeNoise();

        // Compiles, but will cause a run-time error.
	ToyRobot robot = (ToyRobot)toy; 
        robot.recharge();
    }
    
}