ABAP FORM DEFINITION Statement syntax and functionality in SAP

FORM - DEFINITION, IMPLEMENTATION

Short Reference

ABAP Syntax(Obsolete) FORM subr DEFINITION
[TABLES table_parameters ]
[USING parameters ]
[CHANGING parameters ]
[RAISING exc1|RESUMABLE(exc1) exc2|RESUMABLE(exc2) ...].

FORM subr IMPLEMENTATION.
...
ENDFORM.

What does it do? In this variant of the statement FORM
the definition of a subroutine subr is shared between a declaration part and an implementation part:
The statement FORM subr DEFINITION declares the subroutine and its parameter interface. The meaning of the additions is the same as in FORM . A subroutine declaration of this type is part of the global declaration part of a program.

The subroutine is implemented between the statements FORM subr IMPLEMENTATION and ENDFORM . These statements define a processing block in the implementation part of the program.
This form of the definition of a subprogram is required if a subroutine of an encapsulated package is to be called from another prog
ram. In this case, the subroutine must be declared in a definition include. If the calling program is in a different package, the su
broutine declared in the definition include has to be published explicitly in the package interface.

ABAP FORM DEFINITION Statement syntax, information and example SAP source code