單項(xiàng)選擇題

1. class Super { 
2. public float getNum() { return 3.0f; } 
3. } 
4.  
5. public class Sub extends Super { 
6.  
7. } 
Which method, placed at line6, causes compilation to fail?()  

A. public void getNum(){}
B. public void getNum(double d){}
C. public float getNum() { return 4.0f; }
D. public double getNum(float d) { return 4.0d; }

微信掃碼免費(fèi)搜題