Subject: SAP-ABAP (Advanced Business Application Programming)
With the evolution of SAP ABAP from a procedural to an object-oriented programming language, mastering advanced OOP concepts has become crucial for SAP developers. Concepts like Inheritance, Polymorphism, and Interfaces enable the creation of modular, reusable, and flexible code — essential for scalable SAP applications.
This article delves into these advanced object-oriented programming principles in the context of SAP ABAP, explaining their significance, implementation, and practical use cases.
Inheritance is a core concept of OOP where a class (called the subclass or child class) inherits attributes and methods from another class (called the superclass or parent class). This promotes code reuse and establishes an "is-a" relationship between classes.
INHERITING FROM keyword to define a subclass.CLASS vehicle DEFINITION.
PUBLIC SECTION.
METHODS: start,
stop.
ENDCLASS.
CLASS vehicle IMPLEMENTATION.
METHOD start.
WRITE 'Vehicle started'.
ENDMETHOD.
METHOD stop.
WRITE 'Vehicle stopped'.
ENDMETHOD.
ENDCLASS.
CLASS car DEFINITION INHERITING FROM vehicle.
PUBLIC SECTION.
METHODS: open_trunk.
ENDCLASS.
CLASS car IMPLEMENTATION.
METHOD open_trunk.
WRITE 'Trunk opened'.
ENDMETHOD.
ENDCLASS.
START-OF-SELECTION.
DATA: my_car TYPE REF TO car.
CREATE OBJECT my_car.
my_car->start( ). "Inherited method
my_car->open_trunk( ). "Subclass method
Polymorphism allows objects of different classes related by inheritance to be treated as objects of a common superclass. It enables a single interface to represent different underlying forms (data types).
CLASS vehicle DEFINITION.
PUBLIC SECTION.
METHODS: start REDEFINITION.
ENDCLASS.
CLASS vehicle IMPLEMENTATION.
METHOD start.
WRITE 'Starting generic vehicle'.
ENDMETHOD.
ENDCLASS.
CLASS car DEFINITION INHERITING FROM vehicle.
PUBLIC SECTION.
METHODS: start REDEFINITION.
ENDCLASS.
CLASS car IMPLEMENTATION.
METHOD start.
WRITE 'Starting car'.
ENDMETHOD.
ENDCLASS.
START-OF-SELECTION.
DATA: v TYPE REF TO vehicle,
c TYPE REF TO car.
CREATE OBJECT c.
v = c. "Polymorphic assignment
v->start( ). "Calls car's start method due to dynamic binding
An interface is a contract that defines a set of methods without implementation. Classes that implement an interface promise to provide concrete implementations for all its methods. Interfaces facilitate multiple inheritance of types, as ABAP classes can implement multiple interfaces but inherit from only one superclass.
INTERFACE keyword to define an interface.INTERFACES keyword.INTERFACE if_drivable.
METHODS: start,
stop.
ENDINTERFACE.
CLASS vehicle DEFINITION.
PUBLIC SECTION.
INTERFACES if_drivable.
ENDCLASS.
CLASS vehicle IMPLEMENTATION.
METHOD if_drivable~start.
WRITE 'Vehicle started'.
ENDMETHOD.
METHOD if_drivable~stop.
WRITE 'Vehicle stopped'.
ENDMETHOD.
ENDCLASS.
START-OF-SELECTION.
DATA: v TYPE REF TO if_drivable.
CREATE OBJECT v TYPE vehicle.
v->start( ).
| Concept | Definition | Key Benefits |
|---|---|---|
| Inheritance | Subclass inherits properties and behaviors from superclass | Code reuse, hierarchical design |
| Polymorphism | Objects behave differently based on their actual class at runtime | Flexibility, dynamic binding |
| Interfaces | Defines a contract of methods without implementation | Decoupling, multiple inheritance |
Advanced OOP concepts such as Inheritance, Polymorphism, and Interfaces form the backbone of modern SAP ABAP development. By leveraging these principles, developers can build scalable, maintainable, and flexible applications that meet evolving business needs.
Mastering these concepts is essential for any SAP ABAP professional aiming to transition from procedural programming to truly object-oriented design and development.