Nested Counter Loop in ABAP

[Former Member]

Hey everyone,

is there a simpler/better way to make a nested counter loop than this?

  DATA(XCOUNT) = 0.
  DATA(YCOUNT) = 0.
  DO X TIMES.
    XCOUNT = XCOUNT + 1.
    DO Y TIMES.
      YCOUNT = YCOUNT + 1.
      DO=>SOMETHING( X = XCOUNT Y = YCOUNT ).
    ENDDO.
    YCOUNT = 0.
  ENDDO.
  XCOUNT = 0.

[MateuszAdamus]

Hello Former Member

From SAP Help (https://help.sap.com/doc/abapdocu_750_index_htm/7.50/en-US/abapdo.htm): SY-INDEX always refers to the current LOOP

Which means you could do something like:

  DATA(XCOUNT) = 0.
  DO X TIMES.
    XCOUNT = XCOUNT + 1.
    DO Y TIMES.
      DO=>SOMETHING( X = XCOUNT Y = sy-index ).
    ENDDO.
  ENDDO.
  XCOUNT = 0.

You could also store X count in the class:

DO x TIMES.
  do=>set_x( sy-index ).
  DO y TIMES.
    do=>something( y = sy-index ).
  ENDDO.
ENDDO.

METHOD something.
  WRITE: / do=>x.
  WRITE: / y.
ENDMETHOD.

Kind regards,

Mateusz

[matt]

Not fundamentally, but xcount and ycount are clearly helper variables and won't have use outside of the code you've posted, so something like:

DATA(XCOUNT) = 0.
DO XCOUNT TIMES.
  DATA(YCOUNT) = 0.
  XCOUNT = XCOUNT +1.
  DO YCOUNT TIMES.
      YCOUNT = YCOUNT + 1.
      DO=>SOMETHING( X = XCOUNT Y = YCOUNT ).
  ENDDO.
ENDDO.

or

DATA(XCOUNT) = 0.
DO XCOUNT TIMES.
  XCOUNT = XCOUNT + 1.
  yloop( XCOUNT ).
ENDDO.

METHOD yloop.
  DATA(YCOUNT) = 0.
  DO YCOUNT TIMES.
      YCOUNT = YCOUNT + 1.
      DO=>SOMETHING( I_X = I_X I_Y = YCOUNT ).
  ENDDO.
ENDMETHOD.

[Sandra_Rossi]

Your code is so simple to understand that I don't see why you want to improve it. The only weird thing is common to many developers, is the "reset after execution" ("?count = 0"), as it's prone to errors and can be generally avoided. Instead, you should always prefer the "reset before execution" (move DATA(YCOUNT) = 0 before DO Y TIMES, and remove the 2 lines ?count = 0).

But if it's for the fun/NOT a productive code, you may declare DO=>SOMETHING with a dummy returning parameter and do like this (I use ASSERT here, but I could use anything else, it's just to say that the result is always 1 and has no importance for the objective):

ASSERT 1 = REDUCE i( INIT i = 1
    FOR xcount = 1 THEN xcount + 1 WHILE xcount <= x
    FOR ycount = 1 THEN ycount + 1 WHILE ycount <= y
    LET dummyresult = DO=>SOMETHING( X = XCOUNT Y = YCOUNT ) IN
    NEXT i = 1 ).

WARNING: stunt[wo]men, don't try this at home and at work!