Java OCA OCP Practice Question 1309

Question

How many compiler errors does the following code contain? 

package mypkg; //  w w w.  jav  a2s.c  o  m
interface CanFly { 
   public void fly() {} 
} 
final class Bird { 
   public int fly(int speed) {} 
} 
public class Eagle extends Bird implements CanFly { 
   public void fly() {} 
}
  • A. None
  • B. One
  • C. Two
  • D. Three 


D.

Note

interfaces can only contain abstract, final, and default methods.

The method fly() defined in CanFly is not marked static or default and defines an implementation, an empty {}, meaning it cannot be assumed to be abstract; therefore, the code does not compile.

The implementation of fly(int speed) in the Bird class also does not compile, but not because of the signature.

The method body fails to return an int value.

Since it is an overloaded method, if it returned a value it would compile without issue.

The Eagle class does not compile because it extends the Bird class, which is marked final and therefore, cannot be extended.

For these three reasons, Option D is the correct answer.




PreviousNext

Related