Editing ABAP (section)

==ABAP Objects==
The ABAP language supports [[object-oriented programming]], through a feature known as "ABAP Objects".<ref>{{citation|chapter=Classes|title=SAP NetWeaver 7.0|chapter-url=http://help.sap.com/saphelp_nw70/helpdata/en/c3/225b5c54f411d194a60000e8353423/frameset.htm|access-date=10 August 2009|archive-date=28 November 2009|archive-url=https://web.archive.org/web/20091128103138/http://help.sap.com/saphelp_nw70/helpdata/en/c3/225b5c54f411d194a60000e8353423/frameset.htm|url-status=live}}</ref> This helps to simplify applications and make them more controllable.

ABAP Objects is fully compatible with the existing language, so one can use existing statements and modularization units in programs that use ABAP Objects, and can also use ABAP Objects in existing ABAP programs.  Syntax checking is stronger in ABAP Objects programs, and some syntactical forms (usually older ones) of certain statements are not permitted.

Objects form a capsule which combines the character to the respective behavior. Objects should enable programmers to map a real problem and its proposed software solution on a one-to-one basis. Typical objects in a business environment are, for example, ‘Customer’, ‘Order’, or ‘Invoice’. From Release 3.1 onwards, the Business Object Repository (BOR) of SAP Web Application Server ABAP has contained examples of such objects. The BOR object model will be integrated into ABAP Objects in the next Release by migrating the BOR object types to the ABAP class library.
A comprehensive introduction to object orientation as a whole would go far beyond the limits of this introduction to ABAP Objects. This documentation introduces a selection of terms that are used universally in object orientation and also occur in ABAP Objects. In subsequent sections, it goes on to discuss in more detail how these terms are used in ABAP Objects. The end of this section contains a list of further reading, with a selection of titles about object orientation.

* ''Objects'' are instances of classes. They contain data and provide services. The data forms the attributes of the object. The services are known as methods (also known as operations or functions). Typically, methods operate on private data (the attributes, or state of the object), which is only visible to the methods of the object. Thus the attributes of an object cannot be changed directly by the user, but only by the methods of the object. This guarantees the internal consistency of the object.
* ''Classes'' describe objects. From a technical point of view, objects are runtime instances of a class. In theory, any number of objects based on a single class may be created. Each instance (object) of a class has a unique identity and its own set of values for its attributes.
* ''Object References'' are unique addresses that may be used to identify and point to objects in a program. Object references allow access to the attributes and methods of an object.

In object-oriented programming, objects usually have the following properties:

* Encapsulation – Objects restrict the visibility of their resources (attributes and methods) to other users. Every object has an interface, which determines how other objects can interact with it. The implementation of the object is encapsulated, that is, invisible outside the object itself.
* Inheritance – An existing class may be used to derive a new class. Derived classes inherit the data and methods of the superclass. However, they can overwrite existing methods, and also add new ones.
* Polymorphism – Identical (identically named) methods behave differently in different classes. In ABAP Objects, polymorphism is implemented by redefining methods during inheritance and by using constructs called interfaces.