1. public class Boxer1 {
2. Integer i;
3. int x;
4. public Boxer1(int y) {
5. x=i+y;
6. System.out.println(x);
7. }
8. public static void main(
String[] args) {
9. new Boxer1(new Integer(4));
10. }
11. }
The Ans for this is 'NullPointerException' at runtime. Can some one let me know why is it giving that Exception?