Object Oriented ABAP

We can not invoke the new method defined in the class b xyz() using base class obj_a
reference variable.
obj_a = obj_b.
call method : obj_a->xyz. Is not possible. It will throw an error.
In this case we can only call
call method : obj_a->fall,
obj_a->rise.
When we call obj_a->fall , it will call the method of base class since it is not redefined in
sub class b.
When we call obj_a->rise, it will call the method of sub class since it is redefined in sub
class b. For this we can use the table of section 2.3.
2.5 Output of section 2.1
We can now verify the output of code given in section 2.1 from the table described in
section 2.3
We will just see the START-OF-SELECTION and END-OF-SELECTION events below from
section 2.1
******************************************************************
* 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()
Here obj_a refers to base class object so it only calls base class methods rise() and fall().
Since method fall() is not redefined in class b and is just inherited from class a , so when
we call obj_b1->fall, the base class method is invoked.