Subroutines in SAP

DPM125 — Fri, 01 Aug 2025 13:43:35 +0000

A subroutine is a block of reusable code defined using FORM and called using PERFORM. It is a procedural method of modularization mainly used in classical ABAP programming.

When to use:

In classic procedural ABAP programs.
For logic reuse in the same or other programs via INCLUDE.

*&---------------------------------------------------------------------*
*& Report  ZREP_LCLCLASS
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT zrep_lclclass.

DATA: lv_a TYPE i VALUE 5,
      lv_b TYPE i VALUE 10,
      lv_result TYPE i VALUE 0.

WRITE: / 'Before subroutine call:',
       / 'lv_a =', lv_a,
       / 'lv_b =', lv_b,
       / 'lv_result =', lv_result.

* Call the subroutine
PERFORM calculate_sum USING    lv_a     " passed by value (copy)
                              lv_b     " passed by value (copy)
                       CHANGING lv_result.  " passed by reference (direct)

WRITE: / 'After subroutine call:',
       / 'lv_a =', lv_a,
       / 'lv_b =', lv_b,
       / 'lv_result =', lv_result.

*------------------------------------------------------------------*
* Subroutine Definition
*------------------------------------------------------------------*
FORM calculate_sum USING    p_a TYPE i
                            p_b TYPE i
                   CHANGING p_sum TYPE i.

  p_a = p_a + 1.  " Modifies copy (no effect on lv_a)
  p_b = p_b + 1.  " Modifies copy (no effect on lv_b)

  p_sum = p_a + p_b.  " Modifies original lv_result (by reference)

ENDFORM.

Output:

subroutine – SAP EWM Help

Subroutines in SAP

When to use: