ARTICLE
Subroutines
Before the introduction of ABAP Objects, subroutines were mainly used
for the local modularization of programs, however, they can also be
called externally. Their functionality is implemented between the
statements FORM and ENDFORM
. A subroutine is declared either directly when implemented or by
using the statement FORM ... DEFINITION
.
Subroutines should no longer be created in new programs for the
following reasons:
The parameter interface has clear weaknesses when compared with the
parameter interface of methods, such as:
positional parameters instead of keyword parameters
no genuine input parameters in pass by reference
typing is optional
no optional parameters
Every subroutine implicitly belongs to the public interface of its
program. Generally this is not desirable.
Calling subroutines externally is critical with regard to the assignment
of the container program to a program
group in the internal session. This assignment cannot generally be
defined as static.
In those places where subroutines cannot yet be replaced by methods (
PERFORM ON COMMIT|ROLLBACK ,
GENERATE SUBROUTINE POOL ),
they should be used purely as wrappers for method calls and must not
contain any other functional coding.
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved