(ABAP) How to know whether initial screen (selection-screen) is filled or not

Question

first I'm Sorry if my question is too simple I've just learned about ABAP

i have code ini ABAP which uses Selection screen with SELECT-OPTION let say the name is "selection_kunnr" and I want to know if user fill that selection area or not

(not means user leaves the field empty)

note: this selection field (selection_kunnr) is not a mandatory field.

how Can I deal with it?

I have tried using

    if selection_kunnr is not initial.
    "do some action here
    endif.

but I think it doesn't work at all.

Thanks All :)

Answer 1

SELECT-OPTIONS create an internal table (same as the RANGE statement) for a field. (It creates 4 fields: SIGN, OPTION, LOW and HIGH). You can check whether the table has any contents by using:

IF SELECTION_KUNNR[] IS INITIAL.

The [] operator specifies the contents (rows) of an internal table.

I am not sure anymore, because I am not in front of an SAP system right now, but if only the initial FROM/TO fields are filled, I am not sure whether this creates an entry in the table.

HINT: In the ABAP editor, you can place the cursor on any statement, and press F1 to get help on that statement.

Answer 2

Given that this creates an internal table you can also use the DESCRIBE statement. Which works just as well on ranges and internal tables in your program.

DESCRIBE TABLE LINES w_count.