class Dog { }
class Harrier extends Dog { }
class DogTest {
public static void main(String [] args) {
Dog d1 = new Dog();
Harrier h1 = new Harrier();
Dog d2 = h1;
Harrier h2 = (Harrier) d2;
Harrier h3 = d2;
}
}
下面哪一項是正確的?()
A.編譯失敗
B.2個Dog對象被創(chuàng)建
C.2個Harrier對象被創(chuàng)建
D.3個Harrier對象被創(chuàng)建