Difference btwn at new and on change of

Question

Hi all,
can i know the difference between 'at new' and 'on change of'.

Answer 1

Hi,
at new - > means inside the loop, the new value.
eg :
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loop at itab
at new matnr
write matnr.
end at.
end loop.
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On change of -> chnage of particular value inside the loop.
The Major Difference is :
a) When AT NEW occurs,
the alpha-numeric fields have ******* in their value,
b) where as in case of ON CHANGE,
the alpha-numeric fields have their corresponding value,
of that particular record,
where the Event gets fired.
Other differences are :
ON CHANGE OF can be used any where in the program..
on change of differs from at new in the following respects:
1.It can be used in any loop construct, not just loop at. For example, it can be used within select and endselect, do and enddo, or while and endwhile, as well as inside get events.
2.A single on change of can be triggered by a change within one or more fields named after of and separated by or. These fields can be elementary fields or field strings. If you are within a loop, these fields do not have to belong to the loop.
3.When used within a loop, a change in a field to the left of the control level does not trigger a control break.
4.When used within a loop, fields to the right still contain their original values; they are not changed to contain zeros or asterisks.
5.You can use else between on change of and endon.
6.You can use it with loop at it where . . ..
7.You can use sum with on change of. It sums all numeric fields except the one(s) named after of.
8.Any values changed within on change of remain changed after endon. The contents of the header line are not restored as they are for at and endat.
while
AT NEW can be used only within a loop of an INTERNAL TABLE..
5. Sample program to get the taste of it
(just copy paste)
6.
REPORT ABC.
DATA : BEGIN OF ITAB OCCURS 0,
bukrs like t001-bukrs,
f1(10) type c,
end of itab.
itab-bukrs = '1000'.
itab-f1 = '1111111'.
append itab.
itab-bukrs = '1100'.
itab-f1 = '3333333'.
append itab.
itab-bukrs = '1200'.
itab-f1 = '555555'.
append itab.
AT NEW
loop at itab.
at new bukrs.
write :/ itab-bukrs , itab-f1.
endat.
endloop.
AT ONCHANGE
loop at itab.
ON CHANGE OF ITAB-BUKRS.
write :/ itab-bukrs , itab-f1.
ENDON.
Regards,
Ferry Lianto