Object Oriented ABAP

METHOD xyz.
write : / 'Child class b new method --------- xyz()'.
ENDMETHOD. "xyz
ENDCLASS. "b IMPLEMENTATION
********End of Class Definition and implementations***************
***Global declaration
***Creating reference variables for the classes defined above
data :
*Reference variable of type class a
obj_a type ref to a,
*Reference variable of type class b
obj_b1 type ref to b,
*Reference variable of type class b
obj_b2 type ref to b.
***********************************
******************************************************************
* START-OF-SELECTION
*******************************************************************
START-OF-SELECTION.
create object : obj_a,
obj_b1,
obj_b2.
******************************************************************
* END-OF-SELECTION
*******************************************************************
END-OF-SELECTION.
call method : obj_a->fall,
obj_a->rise,
obj_b1->fall.
Now output of above code is :
Super class a-----------fall()
Super class a-----------rise()
Super class a-----------fall()
We will just discuss how we got this output and what will happen when we assign subclass
objects to reference variables of parent class.
2.2 Binding
We have reference variables
obj_a , obj_b1 ,obj_b2
Further we created object obj_a (refers to object of class a) and obj_b1(refers to object of
class b) using create object statement.
When we assign