ABAP Keyword Documentation → ABAP - Reference → Calling and leaving program units → Calling Processing Blocks → Calling Procedures → Method Calls → Static Method Calls
meth( ... ) - Functional Method Call
Other versions: 7.31 | 7.40 | 7.54
Syntax
... { static_meth( )
| static_meth( a )
| static_meth( p1 = a1 p2 = a2 ... )
| static_meth( [EXPORTING
p1 = a1 p2 = a2 ...]
[IMPORTING p1 = a1 p2 = a2 ...]
[CHANGING p1 = a1 p2 = a2 ...] ) } ...
Effect
Functional call of a
functional method static_meth
in a suitable
reader position for functions and expressions.
The return value of the method declared using
RETURNING is used as an operand and its full typing determines the data type of the operand. The actual parameters bound to
output parameters and
input/output parameters are handled in the same way as in
standalone method calls.
The semantics of the syntax used to pass parameters is the same as in standalone method calls. The following differences from standalone method calls exist:
-
The return value in functional method calls cannot be assigned to an actual parameter explicitly using
RECEIVING
. - Inline declarations are not possible for actual parameters.
-
Non-class-based exceptions cannot be handled using
EXCEPTIONS
.
If the return value method has a structured data type, a functional method call can, like a structure, be specified in front of the
structure component selector -
to access a component of the structure.
If the functional method has the same name as a predefined function, the functional method is always called.
Notes
-
In functional method calls, class-based exceptions propagated from the method can be handled as usual in a
TRY
control structure or propagated further. The non-class-based exceptions of a functional method, however, always produce a runtime error. - The same applies to resumable exceptions in functional method calls as in all other methods. If processing can be resumed successfully, execution of the statement called in the method can be completed.
- Method chaining is possible in the operand positions where functional methods can be specified.
-
A functional method call whose first method is an instance method can be introduced using the instance
operator
NEW
or the casting operatorCAST
. - A single functional method call can be used as a predicative method call and as a relational expression.
- Functional method calls can be nested in any way, which means that inline declarations for actual parameters can produce confusing results. For this reason, inline declarations are not allowed.
-
If successful, each method call sets the system field
sy-subrc
to 0, which means that all statements with functional method calls modify the value of this field.
Example
Functional call of a method. Unlike in the example for standalone method calls, the return value is assigned to the result. The inline declarations made in that example, however, are not possible here.
CLASS c1 DEFINITION.
PUBLIC SECTION.
CLASS-METHODS do_something IMPORTING p1 TYPE i
p2 TYPE i
EXPORTING p3 TYPE i
p4 TYPE i
RETURNING VALUE(r) TYPE i.
ENDCLASS.
CLASS c1 IMPLEMENTATION.
METHOD do_something.
...
ENDMETHOD.
ENDCLASS.
DATA: a1 TYPE i,
a2 TYPE i.
START-OF-SELECTION.
DATA(result) =
c1=>do_something( EXPORTING p1 = 333
p2 = 444
IMPORTING p3 = a1
p4 = a2 ).
Example
The functional method
factorial
in this example has the return value fact
of type i
, used on the right side of an assignment in an expression.
CLASS math DEFINITION.
PUBLIC SECTION.
METHODS factorial
IMPORTING n TYPE i
RETURNING value(fact) TYPE i.
ENDCLASS.
CLASS math IMPLEMENTATION.
METHOD factorial.
fact = COND #( WHEN n = 0
THEN 0
ELSE
REDUCE #(
INIT f = 1
FOR i = 1 UNTIL i > n
NEXT f = f * i ) ).
ENDMETHOD.
ENDCLASS.
START-OF-SELECTION.
DATA(result) = 100 + NEW math( )->factorial( 4 ).
Example
The functional method
get
in this example has a structured return value whose component carrname
is accessed.
CLASS carriers DEFINITION.
PUBLIC SECTION.
METHODS get
IMPORTING carrid TYPE scarr-carrid
RETURNING VALUE(r) TYPE scarr.
ENDCLASS.
CLASS carriers IMPLEMENTATION.
METHOD get.
SELECT SINGLE *
FROM scarr
WHERE carrid = @carrid
INTO @r.
ENDMETHOD.
ENDCLASS.
START-OF-SELECTION.
cl_demo_output=>display( NEW carriers( )->get( 'LH' )-carrname ).