Hi Friends what are the actual differences between AT NEW & ON CHANGE

Question

what are the actual differences between  AT NEW & ON CHANGE ? can you list some of the differences?

Answer 1

Hi,
At New
1. When a new record comes at new triggers. Atnew only used inside loop and endloop.
2. At new is controlbreak statment on at new the left side field change, the event
trigers and the values become 0 and *
On Change
1. On change of works same like at-new but the diff is it can be used out side of a loop,like select and endselect,case endcase.
2.. on change of is not a control break statement and we can use onchange of out side the loop
and
The Major difference between the two is that AT NEW can be used ONLY for INTERNAL TABLES, while ON CHANGE OF can be used for any loop processing i.e do..enddo, while..endwhile and loop..endloop also.
AT NEW <field>
The block will be executed when the SY-TABIX is 1 (or) when the SY-TABIX 1 value has a change with the SY-TABIX value.
With this block the field towards the right to the field are not accessable with in the block, and are shown with '*'. They can be accessed outside the block.
ON CHANGE OF <itab>-<field>
The block also works similar to the AT First. In this block all the fields are accesseble.
ON CHANGE OF triggers whenever there is a change in that particular field.
AT NEW triggers whenever there is a change in the fields before that particular field.ie. if there is a change in that combinations from the first field.
On change off' works on variabels. The 1st time the statement isreached a memory copy is made of the value. The next time the statementis reached, the current value is compared to the stored value. If thereis a difference, the coding between ON... and ENDON. is executed. Youcan use this for a table workarea field, but if you have the table loopin a routine and the routine called several times, you can get unwantedresults. (Check the value of the last loop with the value of the firstnew loop.)
The AT NEW (and others like AT END OF...) are specially for table loopprocessing. The coding between AT new FIELD and ANDAT is triggerdwhenever a the field or any field defined to the left is changed. Yourtable should be sorted by all fields from the left up to the consideredFIELD. Btw all fields to the right contain *, so it can be usefull tohave a second workarea filled to be printed or what ever you want.
REWARD IF HELPFUL
RAAM