SCJP題庫第076題

1. class TestA{

2.   public void start(){System.out.println("TestA");}

3. }

4. public class TestB extends TestA{

5.   public void start(){System.out.println("TestB");}

6.   public static void main(String[] args){

7.     ((TestA)new TestB()).start();

8.   }

9. }

What is the result?

A. TestA

B. TestB

C. Compilation fails.

D. An exception is thrown at runtime.

 

Ans: B

 

解說:

new TestB()是產生TestB的物件，所以start方法為TestB的版本，答案是B