Common Questions and Answers about ABAP/4 and Developments

Common Questions and Answers about ABAP/4 and Developments

1. What is the difference between external & internal subroutine?

2. Why do we use ALV?

3. Why do we use GET CURSOR and what is it?

4. Both the events AT SELECTION-SCREEN and AT USER-COMMAND are processed after user input.
Then what is the difference between these and when we should use what?

Answer :
1. The name itself implies the internal subroutines defined by form /perform.. can be called within the same prog in which they were declared.....external subroutines can be called outside the program.......

2. SAP LIST VIEWER is ALV . its main advantage is by using ALV technique we can find totals ,subtotals ,sort in any order etc there itself in the list output of course we need to write all those functionalities while using ALV...also many functional modules are defined under ALV concept...

3. GETCURSOR is used to trace the position of the cursor in the list ..
suppose we want to double click on any filled in the list and want to trace data using that field we use getcursor .....

4.AT SELECTION-SCREEN is used where you have a seperate selection screen using select-options or parameters where as AT USER-COMMAND is used where no selection screen exists....at.user-command is mainly used while setting pf-status which means creating our own menu with function codes etc...