Confused

[Mary Cole]

Can anybody explain me why the answer is B,SuperB,A,SuperA
This is a question in Dans mock exam and i guess theres been some error here in code as i feel line 5 doesn't make any sense

 class SuperA {String s1="SuperA";}
class SuperB {String s1="SuperB";}
class A extends SuperA {
  String s1="A";
  class B extends SuperB {  // 1
    String s1="B";
    void m1() {
      System.out.print(this.s1 + ",");   // 2
      System.out.print(super.s1 + ",");  // 3
      System.out.print(A.this.s1 + ","); // 4
      System.out.print(A.super.s1);      // 5
    }
  }
  public static void main (String[] args) {
    new A().new B().m1();  // 6
}}
 

[Gian Franco]

Hi Mary,
In line 6 the inner class B and it's enclosing class
A are instantiated and m1() is invoked immediately.
In line 2 this refers to the instance of the inner
class; in line 3 super refers to the superclass (SuperB)
of the inner class and in particular to the value of s1;
in line 4 A.this.s1 refers to the instance of the enclosing
class A and in particular the value of s1.
And coming back to your question line 5 refers to the
superclass of the enclosing class A (SuperA) and in
particular to the value of s1.
Instances of class A are always instances of (instanceof)
class A or SuperA.
class B has no other relationship with A than being
it inner class. With this I mean that it doesn't
extend in any way class A. And can't be an instanceof
A.

Was I clear? Best Regards,

Gian Franco Casula
p.s. the code compiles with no hitches
[ February 26, 2004: Message edited by: Gian Franco Casula ]

[Mary Cole]

Thx,
I missed that it was an innerclass........oversight