Best way to declare and use internal table

Question

Hi all,
As per my knoledge there are various techeniques (Methods) to declare and use the internal tables.
Please Suggest me the Best way to declaring and using internal table ( WITH EXAMPLE ).
Please Give the reason as well how the particular method is good ?
What are benefits of particular method ?
Thanks in advance.
Regards
Raj

Answer 1

Hello Raj Ahir,
There are so many methods to declare an internal table.
Mainly I would like to explain 2 of them mostly used.
1. Using Work Area and
2. With header line.
This with header line concept is not suggestable, because, when we shift the code to oops concept.. it doesn't work... Because OOPS doesn't support the Headerline concept...
But it all depends on the situation.
If you are sure that your program doen't make use of the OOPs concept, you can use HEADER LINE concept. If it invols OOPs use WORK AREA concept.
Now I'l explain these two methods with an example each...
1. Using Work area.
TABLES: sflight.
DATA: it_sflight TYPE TABLE OF sflight.
DATA: wa_sflight LIKE LINE OF it_sflight.
SELECT *
  FROM sflight
  INTO it_sflight
  WHERE <condition>.
  LOOP AT it_sflight INTO wa_sflight.
    WRITE / wa_sflight.
  ENDLOOP.
  In this case we have to transfer data into work area wa_sflight.
We can't access the data from the internal table direclty without work
area.
*<===============================================
2. Using Header line.
  DATA: BEGIN OF it_sflight OCCURS 0,
          carrid LIKE sflight-carrid,
          connid LIKE sflight-connid,
          fldate LIKE sflight-fldate,
        END OF it_sflight.
  SELECT *
    FROM sflight
    INTO it_sflight
    WHERE <condition>.
    LOOP AT it_sflight INTO wa_sflight.
      WRITE / wa_sflight.
    ENDLOOP.
In this case we can directly access the data from the internal table.
Here the internal table name represents the header. for each and every
interation the header line will get filled with new data. If you want to
represnent the internal table body you can use it_sflight[].
*<======================================================
TYPES: BEGIN OF st_sflight,
         carrid LIKE sflight-carrid,
         connid LIKE sflight-connid,
         fldate LIKE sflight-fldate,
       END OF st_sflight.
DATA: it_sflight TYPE TABLE OF st_sflight,
      wa_sflight LIKE LINE OF it_sflight.
This is using with work area.
DATA: it_sflight LIKE sflight OCCURS 0 WITH HEADER LINE.
This is using header line.
<b>REWARD THE POINTS IF IT IS HELPFUL.</b>
Regards
Sasidhar Reddy Matli.
Message was edited by: Sasidhar Reddy Matli
        Sasidhar Reddy Matli