SAP ABAP Module Pool Interview Questions & Answers

Question 1. What Is A Transaction?

Answer :

A transaction is dialog program that change data objects in a consistent way.

Question 2. What Are The Requirements A Dialog Program Must Fulfill?

Answer :

• A user friendly user interface.
• Format and consistency checks for the data entered by the user.
• Easy correction of input errors.
• Access to data by storing it in the data bases.

Question 3. Why Do I Need To Do Dialog Programming?

Answer :

To have your own customized screens and processing.

Question 4. What Does Dialog Programming Consist Of?

Answer :

Screens with their corresponding processing code, Menu, module pool program.

Question 5. What Are The Basic Components Of Dialog Program?

Answer :

• Screens (Dynpros)
• ABAP/4 module Pool. 
• Transaction code.

Question 6. What Is Dynpro? What Are Its Components?

Answer :

A dynpro (Dynamic Program) consists of a screen and its flow logic and controls exactly one dialog steps. The different components of the dynpro are:

• Flow Logic: calls of the ABAP/4 modules for a screen.
• Screen layout: Positions of the text, fields, and pushbuttons and so on for a screenScreen Attributes: Number of the screen, number of the subsequent screen, and others
• Fields attributes: Definition of the attributes of the individual fields on a screen.

Question 7. Difference Between The Normal Report / Program And Module Pool Program?

Answer :

• Normal report can be run straight away by executing it and usually has selection criteria –Attributes: 1 online program
• Module pool program cannot be run straight away. 
• It first needs to display a screen – attributes: M module pool program.

Question 8. How Can I Identify Which Button Is Pressed?

Answer :

“fctcode” attributes of the button.

Question 9. What Are Pbo And Pai?

Answer :

• Process before output. Code that is executed prior to the display of a screen.
• Process after input. Code that is executed after a button on the screen has been pressed.

Question 10. What Does Pai And Pbo Contain By Default?

Answer :

PBO - MODULE STATUS_0100 - Key / button definitions

PAI - * MODULE USER_COMMAND_0100 How do you handle the code behind the button that was pressed

Question 11. How Many Pbo And Pai Modules Are Allowed For A Screen?

Answer :

one PBO and one PAI

Question 12. If We Do Not Have / Give Menu Bar Than What Will Menu Bar Have By Default?

Answer :

System , help

Question 13. In The Menu Bar Can You Associate A Function Key To A Button?

Answer :

 yes

Question 14. Can We Use Write Statements In Screen Fields? If Not How Is Data Transferred From Field Data To Screen Fields?

Answer :

No,. The system instead transfers data by comparing screen fields names with ABAP/4 variable names. If both names are the same, it transfers screen fields values to ABAP/4 programs fields and Vice Versa.This happens immediately after displaying the screen.

Question 15. Can We Use Flow Logic Control Key Words In Abap/4 And Vice-versa?

Answer :

The flow control of a dynpro consists of a few statements that syntactically resemble ABAP/4 statements .However, we cannot use flow control keywords in ABAP/4 and vice-versa.

Question 16. What Is Gui Status? How To Create /edit Gui Status?

Answer :

A GUI status is a subset of the interface elements used for a certain screen.

The GUI status for a transaction may be composed of the following elements:

• Title bar.
• Menu bar.
• Application tool bar
• Push buttons. 

To create and edit GUI status and GUI title, use the Menu Painter (SE 41).

Question 17. How Does The Interaction Between The Dynpro And The Abap/4 Modules Take Place?

Answer :

• A transaction is a collection of screens and ABAP/4 routines, controlled and executed by a Dialog processor. 
• The Dialog processor processes screen after the screen, thereby triggering the appropriate ABAP/4 processing of each screen .
• For each screen, the system executes the flow logic that contains the corresponding ABAP/4 processing. 
• The control passes from screen flow logic to ABAP/4 code and back.

Question 18. How Does The Dialog Handle User Requests?

Answer :

• When an action is performed, the system triggers the PROCESS AFTER INPUT event.The data passed includes field screen data entered by the user and a function code. 
• A function code is a technical name that has been allocated in a screen Painter or Menu Painter to a menu entry, a push button, the ENTER key or a function Key of a screen. 
• An internal work field (ok-code) in the PAI module evaluates the function code, and the appropriate action is taken.

Question 19. What Is To Be Defined For A Push Button Fields In The Screen Attributes?

Answer :

A function code has to be defined in the screen attributes for the push buttons in a screen.

Question 20. How Are The Function Codes Handled In Flow Logic?

Answer :

• When the User selects a function in a transaction ,the system copies the function code into a specially designated system field called SY-UCOMM.
• This field is Global in ABAP/4 Module Pool.The F-CODE can then be evaluated in the corresponding PAI module. 
• The function code is always passed in exactly the same way, regardless of whether it comes from a screen push button, a menu option, function key or other GUI element.

Question 21. The Function Code Currently Active Is Ascertained By What Variable?

Answer :

SY-UCOMM Variable.

Question 22. What Are The “field” And “chain” Statements?

Answer :

The FIELD and CHAIN flow logic statements let you Program your own checks. 

FIELD and CHAIN tell the system which fields you are checking and Whether the System should Perform Checks in the flow logic or calls an ABAP/4 Module.

Question 23. What Is An “on Input” Statement?

Answer :

• The ABAP/4 module is called only if a field contains the Value other than the initial Value.
• This initial Value is determined by the field’s data Type: blanks for character Fields.
• Zeros for numerics. If the user changes the Fields Value back to its initial value, ON INPUT does not trigger a call.

Question 24. What Is An “on Request” Statement?

Answer :

The ABAP/4 Module is called only if the user has entered the value in the field value since the last screen display .

The Value counts as changed Even if the User simply types in the value that was already there .In general ,the ON REQUEST condition is triggered through any Form of” MANUAL INPUT’.

Question 25. What Is An On”*-input” Statement?

Answer :

The ABAP/4 module is called if the user has entered the “*” in the first character of the field, and the field has the attribute *-entry in the screen Painter.
You can use this option in Exceptional cases where you want to check only fields with certain Kinds of Input.