# Intro to ABAP - Chapter 06

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```							               Control Statements

BC170_2.06.1
Objectives

• The participants will be able to:
– Use the basic Control Flow Constructs that are
available in the ABAP Editor
– Use the following statements in an ABAP
Program
• IF, CASE, DO, WHILE, ON CHANGE OF,
CHECK, EXIT, and CONTINUE
– Use the Logical Expressions that are available
in the ABAP Editor

BC170_2.06.2
Basic Flow Control in ABAP

BC170_2.06.3
The IF Statement
IF X = 5.
WRITE:/ ‘The value of X is 5’.
ELSEIF X = 6.
WRITE:/ ‘The value of X is 6’.
ELSE .
WRITE:/ ‘X is neither 5 nor 6’.
ENDIF.

BC170_2.06.4
Logical Expressions
Logical Expressions use :
– RELATIONAL OPERATORS
– LOGICAL OPERATORS
– STRING COMPARISON OPERATORS

BC170_2.06.5
Relational Operators
Comparison                     Syntax
Is Equal to                     =, EQ
Is not equal to               < >, ><, NE
Greater than                    >, GT
Greater than or equal to     > =, = >, GE
Less than                        <, LT
Less than or equal to         <=, =<, LE

BC170_2.06.6
Logical Operators

NOT
AND
OR

The hierarchy of the logical
operators is:
NOT, AND, and then OR.
(i.e., different from creating views)
BC170_2.06.7
Good Programming Practice with
Logical Operators

If not ( X = 0 )
or not ( Y = 1 and
Z = X or X = 3
and ( Z = 5 )

BC170_2.06.8
String Comparison Operators
Comparison                Syntax
Contains only               CO
Contains any                CA
Contains string             CS
Contains pattern            CP
Contains not only           CN
Contains not any            NA
Contains no string          NS
Contains no pattern         NP

BC170_2.06.9
The CASE Statement
DATA: year(4) type c.
…..some code to fill year variable with data…..
CASE year.
WHEN ‘1997’.
FORMAT COLOR 6.
WHEN ‘1998’.
FORMAT COLOR 2.
WHEN OTHERS.
FORMAT COLOR 1.
ENDCASE.

BC170_2.06.10
The DO Loop
DO.                             J =4.
WRITE :/ ‘Hello world!’.      DO J TIMES.
ENDDO.                              WRITE :/ ‘Hello world!’.
ENDDO.

BC170_2.06.11
The WHILE Loop
If expression evaluates to    If expression evaluates to
TRUE, code in loop is         FALSE, code in loop is NOT
executed.                     executed, and control
moves to after ENDWHILE.

BC170_2.06.12
Nested Loops and Control Structures
DO 2 TIMES.
WRITE :/ SY-INDEX.
DO 3 TIMES.
WRITE : / ‘ ‘, SY-INDEX.
ENDDO.
ENDDO.
The source code above would display:
1
1
2
3
2
1
2
3
BC170_2.06.13
The ON CHANGE OF Statement

SELECT * FROM YCUSTOMER.
ON CHANGE OF YCUSTOMER-COUNTRY
OR YCUSTOMER-STATE.
[….]
ENDON.
BC170_2.06.14
ENDSELECT.
The CHECK Statement
DO 10 TIMES.
CHECK SY-INDEX <= 4.
WRITE :/ SY-INDEX.
ENDDO.

BC170_2.06.15
The EXIT Statement
IF SY-SUBRC <>0.
EXIT.
ENDIF.

BC170_2.06.16
The CONTINUE Statement
DO 10 TIMES.
IF SY-INDEX >4.
CONTINUE .
ENDIF.
WRITE :/ SY-INDEX.
ENDDO.

BC170_2.06.17
Summary

• The participants should be able to:
– Use the basic Control Flow Constructs that are
available in the ABAP Editor
– Use the following statements in an ABAP
Program
• IF, CASE, DO, WHILE, ON CHANGE OF,
CHECK, EXIT, and CONTINUE
– Use the Logical Expressions that are available
in the ABAP Editor
BC170_2.06.18

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