ABAP Program is made up of various statements. Every ABAP statement starts with keyword. The ABAP statement could be categorized as
Declarative Statements- begins with declarative keyword to declare user-defined type or data objects.
TYPES, DATA, CONSTANTS, PARAMETERS, SELECT-OPTIONS, TABLES.
Modularization statements defines processing block. Some keywords to define module are
FORM.. ENDFORM, FUCNTION.. ENDFUNCTION, MODULE.. ENDMODULE, METHOD.. ENDMEHTOD.
In ABAP we have event blocks defined using event keywords. Examples of event keywords are
INITIALIZATION, START-OF-SELECTION, END-OF-SELECTION, and so on.
Control Statements or conditional statements controls the flow of ABAP program. Examples of control keywords are
IF.. ELSEIF.. ELSE.. ENDIF, CASE.. ENDCASE, CHECK, EXIT, RETURN.
Call Statements – With call statement you call a modularization block, a transaction, or another program. Examples of call keywords are
PERFROM, CALL FUNCTION, CALL METHOD, CALL TRANSACTION, CALL SCREEN, SUBMIT, LEAVE TO TRANSACTION, etc.
Operational Statements – Operation statements perform some task. Operational keywords are
WRITE, LOOP.. ENDLOOP, READ, APPEND, INSERT, DELETE, MODIFY, SORT, CLEAR, REFRESH, FREE, and many more.
Database access statements for data in database tables
SELECT, INSERT, UPDATE, MODIFY and DELETE.
As we progress in our ABAP course, we will become more familiar with various ABAP statements and ABAP keywords.