1. public class TestQ48 {
2. public static void main (
String[] args){
3. TestQ48 tq = new DerivedQ48();
4. ((DerivedQ48)tq).echoN( tq.paramA );
5. }
6. int paramA = 9 ;
7. }
8. class DerivedQ48 extends TestQ48 {
9. int paramA = 3 ;
10. void echoN( int n ){
11. System.out.println("number is " + n );
12. }
13. }
I didn't understand 9 as output.