The first element of an ABAP statement is the ABAP keyword. This determines the category of the statement. The different statement categories are as follows:
These statements define data types or declare data objects which are used by the other statements in a program or routine. The collected declarative statements in a program or routine make up its declaration part.
Examples of declarative keywords:
TYPES, DATA, TABLES
These statements define the processing blocks in an ABAP program.
The modularization keywords can be further divided into:
· Event Keywords
You use statements containing these keywords to define event blocks. There are no special statements to conclude processing blocks – they end when the next processing block is introduced.
Examples of event keywords are:
AT SELECTION SCREEN, START-OF-SELECTION, AT USER-COMMAND
· Defining keywords
You use statements containing these keywords to define subroutines, function modules, dialog modules and methods. You conclude these processing blocks using the END- statements.
Examples of definitive keywords:
FORM ….. ENDFORM, FUNCTION … ENDFUNCTION, MODULE … ENDMODULE.
You use these statements to control the flow of an ABAP program within a processing block according to certain conditions.
Examples of control keywords:
IF, WHILE, CASE
You use these statements to call processing blocks that you have already defined using modularization statements. The blocks you call can either be in the same ABAP program or in a different program.
Examples of call keywords:
CALL METHOD, CALL TRANSACTION, SUBMIT, LEAVE TO
These keywords process the data that you have defined using declarative statements.
Examples of operational keywords: