BC170_2.06.1

Control Statements

BC170_2.06.2

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_2.06.3

Basic Flow Control in ABAP

BC170_2.06.4

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_2.06.5

Logical Expressions

Logical Expressions use :

–

RELATIONAL OPERATORS

–

LOGICAL OPERATORS

–

STRING COMPARISON OPERATORS

BC170_2.06.6

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

Relational Operators

BC170_2.06.7

Logical Operators

NOT

AND

OR

The hierarchy of the logical

operators is:

NOT, AND, and then OR.

(i.e., different from creating views)

BC170_2.06.8

Good Programming Practice

with

Logical Operators

If not ( X = 0 )
or not ( Y = 1

and

Z = X or X = 3

and ( Z = 5 )

Bad

BC170_2.06.9

String Comparison Operators

Comparison

Syntax

Contains only

Contains any

Contains string

Contains pattern

Contains not only

Contains not any

Contains no string
Contains no pattern

CO

CA

CS

CP

CN

NA

NS

NP

BC170_2.06.10

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_2.06.11

The DO Loop

DO.

WRITE :/ ‘Hello world!’.

ENDDO.

J =4.
DO J TIMES.

WRITE :/ ‘Hello world!’.

ENDDO.

BC170_2.06.12

The WHILE Loop

If expression evaluates

to TRUE, code in loop is
executed.

If expression evaluates to
FALSE, code in loop is NOT
executed, and control
moves to after ENDWHILE.

BC170_2.06.13

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_2.06.14

The ON CHANGE OF

Statement

SELECT * FROM YCUSTOMER.
ON CHANGE OF YCUSTOMER-COUNTRY

OR

YCUSTOMER-STATE.
[….]
ENDON.
ENDSELECT.

BC170_2.06.15

The CHECK Statement

DO 10 TIMES.
CHECK SY-INDEX <= 4.
WRITE :/ SY-INDEX.
ENDDO.

BC170_2.06.16

The EXIT Statement

IF SY-SUBRC <>0.

EXIT.

ENDIF.

BC170_2.06.17

The CONTINUE Statement

DO 10 TIMES.

IF SY-INDEX >4.

CONTINUE .

ENDIF.

WRITE :/ SY-INDEX.

ENDDO.

BC170_2.06.18

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