ABAP DATA COMMON Statement syntax and functionality in SAP

DATA - COMMON PART

Short Reference

ABAP Syntax(Obsolete) DATA BEGIN OF COMMON PART [name].
...
DATA ...
...
DATA END OF COMMON PART [name].

What does it do? This variant of the statement DATA
with the additions BEGIN OF COMMON PART and END OF COMMON PART defines a global interface work area , that can be used jointly by the programs of a program group . All data objects declared between these statements using DATA are part of this common area .
The COMMON PART addition can only be used in the global declaration section of an ABAP program. Multiple common data areas can be declared in a program, but they cannot be nested. Every common data area must be given a unique name using the name addition. You can only omit the name addition if there is just one common data area in a program.
In all programs of a program group that access the data of a common data area, this area must be declared with the same name and exactly the same structure, otherwise there is no guarantee that it will work correctly and non-handleable exceptions can be raised.

Latest notes: The use of common data areas in otherwise independent programs can be very problematic, with regard to both the maintainability and the functions. Therefore, common data areas should no longer be used. The parameter interfaces of procedures are available for exchanging data between programs.
Common data areas for various programs are generally declared in an include program that is embedded in all programs involved. However, multiple use of include programs is no longer recommended.
For more information about issues related to interface work areas, see
Program Groups in External Procedure Calls .

Example ABAP Coding In this example, a common data area struc is declared in the include program part . By incorporating the include program, the three programs param , sum and dis
have shared access to the data area struc if they are part of a program group. The latter is accomplished by loading the programs
sum and disp into the program group of param using external subroutine calls. The subroutine display in the program disp outputs the input values to the program param and the result of the summation in the subroutine summing .
* INCLUDE part.
DATA: BEGIN OF COMMON PART struc,
f1 TYPE i,
f2 TYPE i,
s TYPE i,
END OF COMMON PART struc.

PROGRAM param.
INCLUDE part.
PARAMETERS:
p1 TYPE i DEFAULT 20,
p2 TYPE i DEFAULT 90.
f1 = p1.
f2 = p2.
PERFORM summming IN PROGRAM sum.

PROGRAM sum.
INCLUDE part.
FORM summing.
s = f1 + f2.
PERFORM display IN PROGRAM disp.
ENDFORM.

PROGRAM disp.
INCLUDE part.
FORM display.
WRITE: / f1, f2, s.
ENDFORM.

ABAP DATA COMMON Statement syntax, information and example SAP source code