ABAP General

Q) What is SAP R/3?

SAP R/3 refers to Systems Application and Product for data processing Real-time having a 3 tier architecture i.e. Presentation layer, Application layer and Database layer.

Q) What are the types of ABAP programs?

• Type 1 Executable programs do not require any user dialog. You can fill the selection screen using a variant and output data directly to a list or the spool system
• Type M Module pools (dialog-oriented programs using a large number of screens whose flow logic largely determines the program flow). These need a TCODE to be executed
• Type F Type F programs are known as function groups - containers for function modules, and cannot be started using a transaction code or by entering their name directly
• Type K Type K programs are known as class definitions. You cannot start type K programs using a transaction code or by entering the program name. They are containers for global classes in ABAP Objects .
• Type J You cannot start type J programs using a transaction code or by entering the program name. They are containers for global interface in ABAP Objects . Type J programs are known as interface definitions. Like class definitions, you create interface definitions in the Class Builder.
• Type S Type S programs are known as subroutine pools. They cannot contain screens.You cannot start a type S program using a transaction code or by entering the program name. Instead, they are containers for subroutines, which you can call externally from other ABAP programs.
• Type I Type I programs - called includes - are a means of dividing up program code into smaller, more manageable units.

Q) What are Function groups?

What is the difference between function groups and function modules? Function Groups act as containers for Function Modules that logically belong together.
Function Groups

1. These cannot be defined in a Function Module.
2. It cannot be called.
3. They are containers for Function Module.

Function Modules

1. These must be defined in a Function Group.
2. It can be called from any program.
3. They are not containers for Function Group.

Q) What are the system fields? Explain?

The ABAP system fields are active in all ABAP programs. They are filled by the runtime environment, and you can query their values in a program to find out particular states of the system. Although they are variables, you should not assign your own values to them, since this may overwrite information that is important for the normal running of the program. However, there are some isolated cases in which you may need to overwrite a system variable. For example, by assigning a new value to the field SY-LSIND, you can control navigation within details lists.