Visibility of Access Specifiers in terms of Inheritance in ABAP OOPs

REPORT  ZCL_OOPS_TEST.

CLASS cl_oops DEFINITION.

  PUBLIC SECTION.

methods: Display.

PROTECTED SECTION.

METHODS: Display1.

PRIVATE SECTION.

METHODS: Display2.

ENDCLASS.


CLASS cl_oops IMPLEMENTATION.

  METHOD display. 

" can be inherited by sub-class and can be called from outside the class.

  WRITE:/ 'Public Method of super class'.

  ENDMETHOD.

METHOD display1. 

" Can be inherited by sub-class, but can not be called from "outside the class.

  write:/ 'Protected Method of super class' .

  ENDMETHOD.

  METHOD display2.

" Can not be inherited by sub class & can not be called from outside the "class.

  write:/ 'Private Method of super class' .

  ENDMETHOD.

  ENDCLASS.

  class cl_sub DEFINITION INHERITING FROM cl_oops.

    public SECTION.
    METHODS display REDEFINITION.


    PROTECTED SECTION.

METHODS: Display1 REDEFINITION.

PRIVATE SECTION.

METHODS: Display2 REDEFINITION.

 ENDCLASS.
    class cl_sub implementation.

      method display.          " Can be inherited.

     WRITE:/ 'Public Method can be inherited by sub class' .

      ENDMETHOD.

      method display1.         " Can be inherited.

     WRITE:/ 'Protected method can be inherited by sub class' .

      ENDMETHOD.

      method display2.         " Can not be inherited .

     WRITE:/ 'Private method can not be inherited by sub class' .

      ENDMETHOD.



      ENDCLASS.

  DATA: d1 TYPE REF TO cl_oops,
        d2 TYPE REF TO cl_oops,
        d3 TYPE REF TO cl_oops,
        d4 type ref to cl_sub,
        d5 TYPE REF TO cl_sub,
        d6 TYPE REF TO cl_sub.

  START-OF-SELECTION.

  create OBJECT d1.
  create OBJECT d2.
  create object d3.
  CREATE OBJECT d4.
  CREATE OBJECT d5.
  CREATE OBJECT d6.

  CALL METHOD d1->display.
  CALL METHOD d2->display1.
  CALL METHOD d3->display2.
  call method d4->display.
  call method d5->display1.
  call method d6->display2.