ABAP (Advanced Business Application Programming) Object-Oriented Programming (OOP) is a programming paradigm that allows you to model your ABAP applications using objects, classes, and methods. OOP in ABAP provides a more structured and modular approach to software development, making it easier to design, maintain, and extend complex applications. Here's an overview of key concepts and components in ABAP OOP:
1. Classes:
In ABAP OOP, a class is a blueprint for creating objects. It defines the structure and behavior of objects belonging to that class.
A class may contain attributes (data members) and methods (functions) that operate on those attributes.
Example of defining a class:
CLASS z_employee DEFINITION. PUBLIC SECTION. DATA: employee_id TYPE i, employee_name TYPE string.
METHODS: constructor, get_employee_info IMPORTING i_employee_id TYPE i, display_employee_info. ENDCLASS.
2. Objects:
Objects are instances of a class. They represent real-world entities with their own unique data and behavior.
Objects are created from classes using constructors.
Example of creating an object from a class:
DATA: lo_employee TYPE REF TO z_employee.
CREATE OBJECT lo_employee.
3. Methods:
Methods are functions defined within a class. They define the behavior of objects belonging to that class.
Methods can access and manipulate the attributes of an object.
Example of defining methods in a class:
METHOD constructor. " Constructor method for initializing object. ENDMETHOD.
METHOD get_employee_info. " Method to retrieve employee information. ENDMETHOD.
METHOD display_employee_info. " Method to display employee information. ENDMETHOD.
4. Inheritance:
Inheritance allows you to create a new class (subclass) based on an existing class (superclass).
Subclasses inherit attributes and methods from the superclass.
Subclasses can also add their own attributes and methods or override inherited methods.
Example of inheritance:
CLASS z_manager DEFINITION INHERITING FROM z_employee. PUBLIC SECTION. DATA: department TYPE string.
METHODS: constructor REDEFINITION. ENDCLASS.
5. Encapsulation:
Encapsulation is the principle of bundling data (attributes) and methods that operate on that data within a class.
Access to the data is controlled through methods, providing data hiding and protection.
6. Polymorphism:
Polymorphism allows objects of different classes to be treated as objects of a common superclass.
This enables you to write more generic and flexible code.
7. Abstraction:
Abstraction involves defining the essential characteristics of an object while hiding irrelevant details.
Classes provide an abstract representation of real-world objects, focusing on what an object does rather than how it does it.
8. Interfaces:
Interfaces define a contract for classes. A class implementing an interface must provide implementations for the methods defined in that interface.
Interfaces allow you to achieve multiple inheritance-like behavior in ABAP.
Example of defining and implementing an interface:
