Java OCA OCP Practice Question 415

Question

Consider the following code appearing in Bird.java 

class Animal  { /*from w  w  w .j a  v  a 2s .c om*/
    private Animal (){      } 
} 
class Bird extends Animal  {  
    public String name; 
    public Bird (String name){ 
        this.name = name; 
     } 
     
    public static void main (String [] args)  { 
        System.out.println (new Bird ("Bald Bird").name); 
     } 
}

What needs to be done to make this code compile?

Select 1 option 

A. Nothing, it will compile as it is. /*from  www.j a v a  2  s  . c  o  m*/

B. Make Bird class declaration public: 
   public class Bird  {  ...  } 

C. Make the Bird constructor private: 

   private Bird (String name){  ...  } 
   
D. Make Animal constructor public: 
   
   public Animal ()  {  ...  } 
   
E. Insert super(); as the first line in Bird constructor : 

    public Bird (String name){ 
        super (); 
        this.name = name; 
    } 



Correct Option is  : D

Note

If a subclass class constructor doesn't explicitly call the super class constructor, the compiler automatically inserts super(); as the first statement of the base class constructor.

So option 5 is not needed.

Since the constructor of Animal is private, the subclass cannot access it and therefore, it needs to be made public.




PreviousNext

Related