test67.java

来自「SCJP认证考试资料」· Java 代码 · 共 15 行

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 = new Truck();
    FourWheeler fw = new Crane();
    Truck myTruck = new Truck();
    //    du = (DrivingUtilities)myTruck;
    //fw = new Crane();
    fw = (Truck)du;
}