ABAP Keyword Documentation → ABAP − Reference → Declarations → Declaration Statements → Classes and Interfaces → CLASS
CLASS - DEFINITION
Other versions: 7.31 | 7.40 | 7.54
Syntax
CLASS class DEFINITION [class_options].
[PUBLIC SECTION.
[components]]
[PROTECTED SECTION.
[components]]
[PRIVATE SECTION.
[components]]
ENDCLASS.
Effect
The statement block CLASS class DEFINITION - ENDCLASS declares a class named class.
Naming conventions apply to the name class.
components
of the class are declared between CLASS and ENDCLASS. Each component must be included in a
visibility section
after one of the statements PUBLIC SECTION, PROTECTED
SECTION, or PRIVATE SECTION. These statements must be specified in the order above. The class does not need to include all the SECTION statements.
The class options additions
of the statement CLASS can be used to publish a class globally in the class library, define an inheritance relationship, make the class abstract or final, control where the class can be instantiated, and offer
friendship to other classes or interfaces.
Notes
- The class is the smallest encapsulation unit in ABAP Objects. A method can therefore use all components of all instances of the same class apart from the components of its own instance. An exception to this rule are subclasses that cannot access the private components of superclasses if they are not their friends.
-
The declaration part of a class can only be specified in the context described under
CLASS.
Example
Declaration part of a class with statements for declaring static components and instance components.
PUBLIC SECTION.
TYPES:
type1 TYPE ...
CLASS-DATA:
attr1 TYPE ...
...
CLASS-METHODS:
meth1 ...
...
CLASS-EVENTS:
evt1 ...
...
DATA:
attr2 TYPE ...
...
METHODS:
meth2 ...
...
EVENTS:
evt2 ...
...
ENDCLASS.