Intenal table with out headerline

Question

hi,
i have a doubt,please clarify.
data:itab like <databse table> occurs 0 with header line.
or
data:itab like <databse table>occurs 0,
        wa like line type of itab.
in above two cases , in my view  no difference.
in first case there will be one workarea will be created with same name itab,
in second case we are explicitly creating work area.
ok.
here my doubt is in what cases it is madatory to create  internal table with  explicitly work area?
thanks in advance.
venu

Answer 1

hi,
    abap object oriented programming in higher versions doesn't allow internal table with header line, so we can create internal table with out header line.
for that one we follow two approches...
1)
TYPES: BEGIN OF LINE,
         COL1 TYPE I,
         COL2 TYPE I,
       END OF LINE.
DATA :  ITAB TYPE STANDARD TABLE OF LINE,
             WA TYPE LINE.
2) In second case create line type(structure) and row type by using  SE11.
SE11->select DATA ELEMENT object> here select STRUCTURE object and provide required fields>now select ROW TYPE object here provide LINE TYPE( STRCTURE which is created in previous)-> SAVE and activate.
IN the above case STRCTURE acts as WORK-AREA AND ROW TYPE acts as body.
object oriented programming doesn't support to using LIKE key word.
regards,
Ashok