02 introduction to abap programming student version

8/2/2019 02 Introduction to ABAP Programming Student Version

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Spring 2011 Enterprise Programming

INTRODUCTIONTO ABAPPROGRAMMING: SYNTAX

FUNDAMENTALS

From the textbook

Chapter TwoABAP Workbench

Object Navigator (SE80)

Forward navigation

Packages

Transports

Creating database tables

Field names, data elements, and data types

Data element: object that describes the data type and semantic

meaning of a table field (SAP online glossary)

Domain: defines valid value ranges for fields. Similar fields can be

grouped into a domain. Changing that domain changes all the

fields.

Keyword Documentation


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ABAP Variables and Data Types

Data type: description of the kind of data a variable may hold and the

range of acceptable values based on storage allocated.

Technical and (potentially) semantic meaning

Data object: actual variable or constant (of a stated type) that has

been defined.

Complete Data Types

Fixed size, specified format data storage.

Incomplete Data Types

Storage size can vary, so must be set upon variable declaration.

ABAP Standard Data Typesi integer 4 byte whole number +/- 2.1 billion

f float 8 bytes, 15-16 significant digits

c string up to 65k characters

n numeric string up to 65k characters (non-math number)

string string dynamic length up to 2 GB long!

xstring hex string dynamic length byte sequence

x byte sequence up to 65k bytes

d date 8 characters in form YYYYMMDD

t time 6 characters in from HHMMSS

p packed number precise whole or floating number up to 16

bytes

Bold italics indicate incomplete data types (size set on declaration)


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Variable Declarations

DATA varname TYPE [type specification]

Use of chained statements (more typical):

Other variations (considered obsolete) exist.

LIKE can be used to declare a variable based on a prior declaration

DATA age TYPE i. "complete data typeDATA siblings TYPE i VALUE 7. "w/ initialization

DATA state TYPE c LENGTH 2 VALUE 'TN'. "incomplete

DATA: age TYPE i,siblings TYPE i VALUE 7.

When specifying default values for numeric data with decimals, the

value must be placed within single quotes.

DATA state2 LIKE state. "only data type 'copied'

Declaring your own data types

program localTYPES allows declaring local data types that are more specific than

standard types.

TYPES typename TYPE [type specification]

This can be used to give a standard type a more descriptive name for

your application or to more specifically define variable composition.

TYPES cannot have a user-specified default value.

TYPES declarations are local to program. Global type declarations are

possible through use of the ABAP Dictionary, allowing type

management across entire system.

TYPES: userval TYPE i,usercode TYPE n LENGTH 10,

rate TYPE p LENGTH 3 DECIMALS 2.


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Declaring your own data typesglobal

ABAP Dictionary (SE11)

Enter name of type to be created in Data type field.To avoid name collision for class, start your type names with Znn_

Select Create and choose the class of data type.

Describe the data type and provide its technical specification.

Specify how the field will be labeled in reports.

Activate.

Use in programs.

Can generate a list of all repository elements that use the data type.Choose Where-Used List icon from SE11 initial screen.

What is the value of defining and using global data types?

Quick Practice


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Constants

CONSTANTS allows specification of fixed data objects.

CONSTANTS name TYPE type VALUE value.

A number of system-maintained constants exists. These are all within

structure SYST. Can see list through dictionary, data type SYST.

Reference values by using the identifier SY-COMPONENT. For example,

SY-MANDT will display the current client number.

CONSTANTS a_const TYPE d VALUE '19681214'.

CONSTANTS b_con TYPE p LENGTH 3 DECIMALS 2 VALUE'37.46'.

Arithmetic and assignmentValid arithmetic operators: +, -, *, /, ** (exponentiation), DIV (integer

division), MOD.

Parenthesis can be used to set order of precedence.

Operators and parentheses are keywords and must be separated

from other statement elements by at least one space .

Assignment syntax:

MOVE var2 TO var1.

var1 = var2.

varx = 3 + 7 * 2.

If variables of different type, automatic type conversion attempted.

CLEAR varx. Resets varx to default type-related value.


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Writing output

WRITE is used for basic output.

WRITE 10 'Output'.

Output is written beginning in column 10.

WRITE (3) 'Output'.

Output is written in field of size 3. * used to show number truncation(if any). String truncation note noted.

WRITE (*) 'Output'

Output is written in field of sufficient size, without extra spacing.

WRITE 10(3) 'Output'.

Combination of above techniques.

WRITE / 'Output'.

Output written on the next lineWRITE /10(3) 'Output'.

Combination of above techniques.

ParametersPARAMETERS prompts the user for runtime value at program start.

(Called a selection screen.) Syntax is the same as DATA.

Parameter name must be 8 characters or less.

User is prompted with the parameter name.

DEFAULT can be used to specify a default value in the field.

PARAMETERS age TYPE i.PARAMETERS: var1 TYPE c LENGTH 8,

var2 TYPE i.

PARAMETERS var1 TYPE c LENGTH 8 DEFAULT 'NONE'.


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Quick Practice

Literal textABAP is multilingual. Coding in string literals (prompting, etc.) defeats

language independence and should only be done in testing.

The solution for this is text symbols.

Text symbols belong to each program in the text pool for that program.

The various texts are placed in the text pool and assigned a 3-character

alphanumeric code (xxx).

This code is then used by specifying either

TEXT-xxx instead of the literal.

literal(xxx) where literal is the message in the native language.

Access the text pool to define text symbols by either:

From editor select Goto Text Elements Text Symbols

Using the syntax above to reference a text symbol in coding. Then double

click on the text symbol entered.

Goto Translation will translate the text symbols.


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Logical Expressions

Logical expressions evaluate to true or false.

In ABAP, logical expression cannot be assigned to variables (noboolean data type).

Logical expressions are used in conditional code sequences.

Relational Operators

Operator Operation

=, EQ Is equal to

, NE Is not equal to

, GT Is greater than

=, GE Is greater than or equal to

Boolean Operators

Operator Operation

AND Logical and

OR Logical or

NOT Logical not

NOT is placed before an expressionto negate its result.

NOT var_a LT var_b.

Conditional code execution: IF, ELSEIF, ELSEIF logical_expression.

1 or more statements.

ENDIF.

IF logical_expression.


ELSE.


ENDIF.

IF logical_expression.


ELSEIF logical_expression.


ENDIF.

IF var_a LT var_b.

WRITE / var_a.

ENDIF.

IF var_a LT var_b.

WRITE / var_a.

ELSE.

WRITE / var_b.

ENDIF.

IF var_a LT var_b.

WRITE / var_a.

ELSEIF var_b LT var_c.

WRITE / var_b.

ENDIF.


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Conditional code execution: CASE

CASE data_object.

WHEN value.


WHEN value.


WHEN OTHERS.


ENDCASE.

CASE var_a.

WHEN 1.

WRITE \ 'uno'.

WHEN 2.

WRITE \ 'dos'.

WHEN OTHERS.

WRITE \ 'other'.

ENDCASE.

Quick Practice


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Using the Debugger to test programs

Program must be saved and activated before debugging.

Set a breakpoint indicating where you want the program to stop inthe execution and display the debugger.

Use Direct Processing to begin execution. Program runs to

breakpoint.

In the source code display, double click any variable you wish to

watch.

Add/remove additional breakpoints by single clicking to left of line.

Step through code using controls in upper leftsingle step, execute,

return, continue (runs until next breakpoint).

Watched variable values can be changed.

A watchpoint can be set of a variable and the program will run until

that variable's value changes

Looping

DO value TIMES.


ENDDO.

WHILE condition.


ENDWHILE.

DO.


IF abort_condition.

EXIT.

ENDIF.

ENDDO.

DO var_a TIMES.

WRITE / 'Hi'.

ENDDO.

WHILE var_a < 10.

var_a = var_a * 2.

ENDWHILE.

DO.

var_a = var_a * 2.

IF var_a > 200.

EXIT.

ENDIF.

ENDDO.

ABAP supports definite iteration, pre-test iteration, and post-test

iteration.

Within loops sy-index is a system managed loop counter.


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Exiting Loops

EXIT: Loop exits immediately. Jump to statement that follows loop

block.

CONTINUE: Restart next loop iteration.

CHECK condition: Restart next loop iteration (continue) if false.

WHILE sy-index < 10.WRITE / sy-index.IF sy-index < 3.CONTINUE.

ENDIF.WRITE 'After ENDIF'.ENDWHILE.

WHILE sy-index < 10.WRITE / sy-index.CHECK sy-index < 3.WRITE 'After CHECK'.ENDWHILE.

Quick Practice


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Copyrights

Microsoft, Windows, Excel, Outlook, and PowerPoint are registered trademarks of Microsoft Corporation.

IBM, DB2, DB2 Universal Database, System i, System i5, System p, System p5, System x, System z, System z10, System z9, z10, z9, iSeries, pSeries,xSeries, zSeries, eServer, z/VM, z/OS, i5/OS, S/390, OS/390, OS/400, AS/400, S/390 Parallel Enterprise Server, PowerVM, Power Architecture, POWER6+,POWER6, POWER5+, POWER5, POWER, OpenPower, PowerPC, BatchPipes, BladeCenter, System Storage, GPFS, HACMP, R ETAIN, DB2 Connect, RACF,Redbooks, OS/2, Parallel Sysplex, MVS/ESA, AIX, Intelligent Miner, WebSphere, Netfinity, Tivoli and Informix are trademarks or registered trademarks ofIBM Corporation.

Linux is the registered trademark of Linus Torvalds in the U.S. and other countries.

Oracle is a registered trademark of Oracle Corporation.

HTML, XML, XHTML and W3C are trademarks or registered trademarks of W3C, World Wide Web Consortium, Massachusetts Institute of Technology.

Java is a registered trademark of Sun Microsystems, Inc.

JavaScript is a registered trademark of Sun Microsystems, Inc., used under license for technology invented and implemented by Netscape.

SAP, R/3, SAP NetWeaver, Duet, PartnerEdge, ByDesign, SAP Business ByDesign, and other SAP products and services mentioned herein as well as theirrespective logos are trademarks or registered trademarks of SAP AG in Germany and other countries.

Business Objects and the Business Objects logo, BusinessObjects, Crystal Reports, Crystal Decisions, Web Intelligence, Xcelsius, and other BusinessObjects products and services mentioned herein as well as their respective logos are trademarks or registered trademarks of Business Objects S.A. in theUnited States and in other countries. Business Objects is an SAP company.

Other products mentioned in this presentation are trademarks of their respective owners.

Presentation prepared by and copyright of Dr. Tony

Pittarese, East Tennessee State University, Computer and

Information Sciences Dept. ([email protected])

Podcast lecture related to this presentation available via

ETSU iTunesU.

02 introduction to abap programming student version

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