test67.java~

SCJP认证考试资料

interface DrivingUtilities{}
class FourWheeler implements DrivingUtilities{}
class Car extends FourWheeler {}
class Truck extends FourWheeler{}
class Bus extends FourWheeler{}
class Crane extends FourWheller{}
public class Test67 {
    DrivingUtilities du = null;
    FourWheeler fw = null;
    Truck myTruck = new Truck();
    du = (DrivingUtilities)myTruck;
    fw = new Crane();
    fw = du;
}