About Header Line

Question

what the different between the data between with header line and without header line.
Like
Data: itab type table of spfli with header line.
Data: itab type table of spfil.
Thanks.

Answer 1

Hi,
1) Data: itab type table of spfli with header line.
        The optional addition WITH HEADER LINE declares an extra data object with the same name and line type as the internal table “Itab”. This data object is known as the header line of the internal table. We can use it as a work area when working with the internal table.
      You can use the header line as a work area when you process the internal table. The ABAP statements that you use with internal tables have short forms that you can use if your internal table has a header line. These statements automatically assume the header line as an implicit work area.
2) Data: itab type table of spfil.
        Here we are declaring an Internal table without a HEADER LINE.So while LOOP opertions or table operation we need to Declare a WORK AREA Seperatly of the table (itab).
DATA: wa_itab    LIKE  itab.
Operations without header line
Data: itab type table of spfil.
+++++++++++++++++++++++++++++++++++++++
INSERT wa INTO TABLE itab.
COLLECT wa INTO itab.
READ TABLE itab... INTO wa.
MODIFY TABLE itab FROM wa...
MODIFY itab FROM wa...WHERE...
DELETE TABLE itab FROM wa.
LOOP AT ITAB INTO wa...
APPEND wa TO itab.
INSERT wa INTO itab...
MODIFY itab FROM wa...
Operations with header line
Data: itab type table of spfli with header line.
++++++++++++++++++++++++++++++++++++++++++++++++++
INSERT TABLE ITAB.
COLLECT itab.
READ TABLE itab...
MODIFY TABLE itab...
MODIFY itab... WHERE...
DELETE TABLE itab.
LOOP AT ITAB...
APPEND itab.
INSERT itab...
MODIFY itab...
Hope this will be helpful.
Regards Avi...