What is an Abstract Class in SAP ABAP?

DPM125 — Sun, 03 Aug 2025 06:37:17 +0000

An abstract class is a class that cannot be instantiated directly. It serves as a blueprint for other classes. Abstract classes typically include:

Abstract methods, which are declared but not implemented.
Concrete methods, which can be implemented and inherited.

Feature	Description
Not instantiable	Cannot use `CREATE OBJECT` on abstract classes.
Used for inheritance	Serve as base classes for child classes.
Can contain abstract methods	These must be implemented in subclasses.
Can contain concrete methods	These can be used directly by child classes.

REPORT zrep_lclclass.

CLASS lcl_animal DEFINITION ABSTRACT.
  PUBLIC SECTION.
    METHODS:
      speak ABSTRACT,
      move.         " This can be implemented if needed
ENDCLASS.

CLASS lcl_animal IMPLEMENTATION.
  METHOD move.
    WRITE: 'Animal is moving'.
  ENDMETHOD.
ENDCLASS.

" Concrete subclass
CLASS lcl_dog DEFINITION INHERITING FROM lcl_animal.
  PUBLIC SECTION.
    METHODS:
      speak REDEFINITION.
ENDCLASS.

CLASS lcl_dog IMPLEMENTATION.
  METHOD speak.
    WRITE: 'Woof!'.
  ENDMETHOD.
ENDCLASS.

START-OF-SELECTION.
  " Parent Class
  DATA(lo_animal) = NEW lcl_animal( ).
  lo_animal->speak( ).
  WRITE: 'Animal can speak'.
  SKIP.
  " child class
  DATA(lo_dog) = NEW lcl_dog( ).
  lo_dog->speak( ).
  lo_dog->move( ).

Output:
Check the Program ( CTRL + F2 ).

if not initated the Parent class then the output will be.

Output:

What is Singleton Class ? how to use Singleton class in SAP ABAP ?

DPM125 — Thu, 31 Jul 2025 19:28:18 +0000

A Singleton class is a design pattern that restricts the instantiation of a class to one single object throughout the lifecycle of a program. This is useful when exactly one object is needed to coordinate actions across the system — such as logging, configuration management, or connection handling.

Key Characteristics of Singleton Pattern:

Only one instance of the class exists.
The class controls its own instantiation.
A global access point is provided to access.

*&---------------------------------------------------------------------*
*& Report  ZREP_LCLCLASS
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT zrep_lclclass.

CLASS lcl_class_singleton DEFINITION CREATE PRIVATE.
  PUBLIC SECTION.
  " to check the instance is created or not.
    CLASS-METHODS: m_factory RETURNING VALUE(r_instance) TYPE REF TO lcl_class_singleton.
  " getter and setter methods
    METHODS : get_attribute RETURNING VALUE(r_attribute) TYPE i,
              set_attribute IMPORTING m_attribute TYPE i.

  PRIVATE SECTION.
*    CLASS-DATA: obj_instance TYPE REF TO lcl_class_singleton.
    DATA gv_attribute TYPE i.
ENDCLASS.

class lcl_class_singleton IMPLEMENTATION.
    method m_factory.
        if r_instance is not BOUND.
            r_instance = new lcl_class_singleton( ).
        endif.
   ENDMETHOD.

   method get_attribute.
       r_Attribute = gv_Attribute.
   ENDMETHOD.

   method set_attribute.
     gv_Attribute =  m_attribute.
   ENDMETHOD.
 ENDCLASS.

 START-OF-SELECTION.
 " create an instance of class
   data(lo_obj) =  lcl_class_singleton=>m_factory( ).
 " set the value for the attribute.
   lo_obj->set_attribute( 10 ).

   " try to create another instace of the class.
    data(lo_obj2) = lcl_class_singleton=>m_factory( ).
   " check the attribute of the new instance
   " it should be same as go_obj as it contains a static attribute
   " get the data and print it.
   write: 'First object attribute value ', lo_obj->get_attribute( ).
   write :/ 'Second object attribute value ', lo_obj2->get_attribute( ).

Output:

object – SAP EWM Help

What is an Abstract Class in SAP ABAP?

What is Singleton Class ? how to use Singleton class in SAP ABAP ?

Key Characteristics of Singleton Pattern: