SCJP test

class A {
    public void go(){
       System.out.println("TestA");
    }
    
}

public  class B extends A {
    public void go(){
       System.out.println("TestB");
    }
   
    public static void main(String[] args){
         ((A)new B()).go();
    }
}

   What's the output?

 

   A. TestA

   B. TestB

评论

2 楼 wjmm_84 2009-12-25  

运行了下，确实是B

1 楼 zerostar88 2009-11-19  

The answer is B.

((A)new B()).go(); 

===>it is same to
A b = new B();
b.go();

===> B extends A and it override the method go(), so it will run B.go() when runtime.