class Machine{

public void start(){

System.out.println("Machine started");

}

public void start1(){

System.out.println("Machine started - start1");

}

}

class Camera extends Machine{

public void start(){

System.out.println("Camera started");

}

public void snap(){

System.out.println("Photo taken");

}

public void snap2(){

System.out.println("Photo taken snap2");

}

}

public class UpcastingANDDowncasting {

public static void main(String[] args) {

Machine mach1 = new Machine();

Camera cam1 = new Camera();

mach1.start();

cam1.start();

cam1.snap();

//Upcasting

Machine mach2 = cam1;

mach2.start();

mach2.start1();

//The variable decides which methods can be called

//this won't work. Which implementation are

//determinced by the object.

// mach2.snap();

//Downcasting -- requires brackets () with type of

//Object you're downcasting too.

Machine mach3 = new Camera();

Camera cam2 = (Camera)mach3;

cam2.start();

cam2.snap();

cam2.start1();

cam2.snap2();

//Can't be done -- causes RUNTIME error

// Machine mach4 = new Machine();

// Camera cam3 = (Camera)mach4;

// cam3.start();

// cam3.snap();

}

}