ABAP Keyword Documentation → ABAP − Reference → Declarations → Declaration Statements → Classes and Interfaces → ABAP Objects - Overview → Classes → Components of Classes
Methods of Classes
Methods are internal procedures of a class that determine the behavior of an object. They can access all the attributes of all instances of their class and can therefore change the status of an object. Methods have a parameter interface, used by the system to pass values to them when they are called, and by which they can return values to the caller. The private attributes of a class can only be changed using methods of the same class.
Other versions: 7.31 | 7.40 | 7.54
Definition
A method meth is declared in the
declaration part
of a class using the statements
METHODS and CLASS-METHODS and implemented in the
implementation part of the class using the following
processing block:
METHOD meth. ... ENDMETHOD.
As in all procedures, local data types and data objects can be declared in methods. Methods are called
statically using the expression meth( ... ) or
dynamically using the
statement CALL METHOD (known as a dynamic invoke).
Note
In the methods of a class, one method of the class obscures a built-in function with the same name. This done regardless of the type and number of method parameters and the type and number of arguments on the function. This means that a method should not have the same name as a built-in function.
Instance Methods
Instance methods are declared using the statement METHODS. They can access all the attributes of a class and can trigger all its events.
Note
Any attempt to use an initialobject reference variable to call an instance method raises a catchable exception.
Static Methods
Static methods are declared using the statement CLASS-METHODS. This statement can access
static attributes of a class and it can raise
static events only.
Constructors
As well as the regular methods that are called explicitly,
there are two special methods called constructor
and class_constructor. These are called automatically when an object is created or when a class component is accessed for the first time.
Functional Methods
Functional methods are methods with precisely one
RETURNING parameter and any number of other formal parameters. Functional methods cannot just be called as
standalone statements, but also as
functional method calls in
operand positions for functions and expressions. Here they can be also be combined as
method chainings.
Optional Methods
In interfaces, methods can be made optional using the addition
DEFAULT of the statements METHODS
and CLASS-METHODS. An optional
interface method does not need to be implemented explicitly in a class when an interface is implemented.
Instead, a default behavior is specified for calls of non-implemented methods in the definition.
DEFAULT IGNORE calls an empty method and DEFAULT FAIL raises an exception.
Special Methods
AMDP Methods
AMDP methods are implemented as
ABAP Managed Database
Procedures using the addition BY
DATABASE PROCEDURE or BY DATABASE FUNCTION in a database-specific language and executed in the database system.
Kernel Methods
For internal use, kernel methods are implemented in
the kernel using the addition BY KERNEL MODULE.