ABAP Keyword Documentation → ABAP − Reference → Declarations → Declaration Statements → Classes and Interfaces → Components in Classes and Interfaces → Methods → METHODS
METHODS - parameters
Other versions: 7.31 | 7.40 | 7.54
Syntax
... { VALUE(p1) | REFERENCE(p1) | p1 }
typing [OPTIONAL|{DEFAULT def1}]
{ VALUE(p2) | REFERENCE(p2) | p2 }
typing [OPTIONAL|{DEFAULT def2}]
...
Addition
Effect
Defines formal parameters p1 p2 ... for methods.
VALUE or REFERENCE are used to define whether a parameter p1 p2 ... is passed by
value or by
reference. If only
one name p1 p2 ... is specified, the parameter is passed by reference by default. An input parameter passed by reference cannot be changed in the method.
If the addition typing is used, every formal parameter must be typed. The syntax of typing is described in
Typing Syntax. The typing of a formal parameter causes the data type to be
checked against the typing when an actual parameter is passed. The typing also defines in which operand positions the formal parameter can be used in the method.
Note
If a formal parameter is typed as a reference variable and cannot be changed in the procedure, the type check is performed in the same way as for an up cast. If it can be changed in the procedure, the actual parameter must be compatible with the formal parameter.
Addition
... OPTIONAL|{DEFAULT def}
Effect
OPTIONAL or DEFAULT can be used to define input
parameters and input/output parameters as optional parameters, where DEFAULT
can be used to specify a replacement parameter def1, def2, ... No actual parameter needs to be specified for an optional parameter when the method is called.
The addition OPTIONAL is used to initialize a formal parameter in a type-friendly
way, but the addition DEFAULT passes the value and type of the replacement
parameter def1 def2 ... to the formal parameter. The replacement parameters def1 def2 ... can be any data object visible here that complies with the rules for
checking typing, with the exception of the components of boxed components.
If no actual parameter is specified for a generically typed formal parameter using the addition OPTIONAL when it is called, the type of the formal parameter is completed in accordance with the
rules for generic types.
Note
If a literal is specified after DEFAULT, the same special rules apply as to
literals as actual parameters. Hence, compatibility
may not then be checked in full in all cases. Instead, in method calls where no actual parameter is
specified for the formal parameter, a literal is converted to the data type of the formal parameter and an exception can be raised if the value of the literal does not fit in the value range of this data type.
Example
Declaration of a method with two different specifications of input parameters. If specified, REFERENCE(p2) has the same meaning as p2.
PUBLIC SECTION.
METHODS
meth
IMPORTING
p1 TYPE i
REFERENCE(p2) TYPE i DEFAULT 111
VALUE(p3) TYPE i OPTIONAL.
...
ENDCLASS.