What is the result?

5 thoughts on “What is the result?”

1. n1 – Cannot cast siblings to eachother
   n2 – Cannot re-declare a variable which was already defined in method

   Reply

2. I assume in line n1 and/or line n2 is a typo, as they should differ between each other. If remove n1 or n2 compilation will be acceptable but running result will throw “ClassCastException” on n1 or n2

   1

   Reply

3. Answer D:

   Classes B and C are siblings, so to say, so we cannot cast them to each other. Line 1 attempt to cast class C to class B. So we get the ClassCastException.

   Line 2 is duplicate of line 1, so it causes compilation to fail in the first place. Since there is no suitable option in the answers, we are left to option D.

   4

   Reply

4. class A{
   public void test(){
   System.out.println(“a”);
   }
   }

   class B extends A{
   public void test(){
   System.out.println(“b”);
   }
   }
   public class C extends A{
   public void test(){
   System.out.println(“c”);
   }

   public static void main(String[] args) {
   A b1=new A ();
   A b2=new C ();
   b1=(A)b2;
   A b3=(B) b2;
   A b3=(B) b2;
   b1.test();
   b3.test();

   }
   }
   Should be E

   2

   Reply

5. D: A ClassCastException is thrown only at line n1, but since n2 is identical, there’s a compilation error too.

   1

   1

   Reply