topic Re: ABAP REDUCE with SORT in Application Development and Automation Discussions

ABAP REDUCE with SORT

AdrianDBorja — Mon, 26 Apr 2021 02:50:26 GMT

Not sure if it's a bug or a feature, but I tried to use REDUCE statement in ABAP with an alphanumeric Internal table. Contents of internal table I_TAB(Inline declaration from SELECT statement) after explicit SORT is as follows:

123

234

345

ABC

DEF

Then I executed the ff REDUCE code:

v_string = REDUCE string( INIT text TYPE string sep = '' FOR ls_tab IN i_tab NEXT text = text && sep && ls_tab-field1 sep = ',' ).

The expected output would have been:

"123,234,345,ABC,DEF"

But no, SAP reduced it like this:

"ABC,DEF,123,234,345"

Totally ignoring the sort order of the internal table prior to REDUCE.

Anyone who has any idea what's going on?

Thanks!

Re: ABAP REDUCE with SORT

joltdx — Mon, 26 Apr 2021 04:24:11 GMT

Hi!

The ABAP Documentation for FOR ... IN itab suggests that:

As in LOOP, the order of the lines read depends on the table category or a key specified in cond.

And looking at the ABAP Documentation for LOOP AT itab, Basic Form, we see that:

Standard tables and sorted tables

The lines are read by ascending line numbers in the primary table index. In each loop pass, the system field sy-tabix contains the line number of the current line in the primary table index.

Hashed tables

The lines are processed in the order in which they were inserted into the table, and after a sort using the statement SORT in the sort order. In each loop pass, the system field sy-tabix contains the value 0.

So I guess it all comes down to the type and declaration of your structure and table, if your result is a bug of a feature... 🙂

Re: ABAP REDUCE with SORT

nomssi — Mon, 26 Apr 2021 07:04:51 GMT

I would suggest defining the internal table with EMPTY key or using GROUP BY and with a user-defined ordering

FOR GROUPS group OF elements IN itab GROUP BY ... ASCENDING

Re: ABAP REDUCE with SORT

Sandra_Rossi — Mon, 26 Apr 2021 12:00:02 GMT

Could you show the exact type of I_TAB please?

Re: ABAP REDUCE with SORT

ThorstenHoefer — Mon, 26 Apr 2021 16:31:32 GMT

Please check following code:

TYPES tt_string TYPE STANDARD TABLE OF char100 WITH DEFAULT KEY.
DATA(lt_string) = VALUE tt_string( ( '123' ) ( '234' ) ( '345' ) ( 'ABC' ) ( 'DEF' ) ).
DATA(l_string) = REDUCE string( INIT text TYPE string sep = ''
           FOR ls_tab IN lt_string NEXT text = text && sep && ls_tab sep = ',' ).
WRITE l_string.

The output is:

123,234,345,ABC,DEF

Re: ABAP REDUCE with SORT

AdrianDBorja — Wed, 26 Feb 2025 10:05:37 GMT

it's inline declaration, as in SELECT * FROM TAB INTO TABLE DATA I_TAB

Re: ABAP REDUCE with SORT

AdrianDBorja — Wed, 26 Feb 2025 10:06:29 GMT

thanks. then I guess, better explicitly declared internal table rather than inline to not have unexpected behavior