Hello Sunita,
I hope you got how ,
System.out.println(s+ ","); is printing "inner,"
In the statement , System.out.println(O.this.s);
O.this refers to the inner
class object ,simply because the object that is invoking the method is of inner class type.
It is something like Outer.new Inner()
Hence it prints the
string variable of th inner class. I hope it is clear.