ch3_programmingbasics

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ABAP ProgrammingChapter 3. Programming Basics


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Objectives

Using arithmetical operators

Performing conversions between different data types

Using Date and time data type

Using Currency data type

Building control routines (IF, CASE, DO, WHILE)

Using System variablesCreating a transaction code

2ABAP programmingChapter 3. Programming Basics


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Arithmetical Operations

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For any arithmetical operation, the calculation itself must appear to the right of the =, and the variable to hold the

result to the left. This ensures that only the result variable will be updated in the execution. The resultvariables

value will be overwritten with the new value.

Spaces must always be inserted on either side of the operators, including parenthesis. One space is theminimum, multiple spaces can help lining code up to make it more readable.

Valid arithmetic operators: +, -, *, /, ** (exponentiation), DIV (integer division), MOD.

Assignment syntax. You can use the MOVE statement to transfer the contents of a data object into another data object.

MOVE var2 TO var1.

var1 = var2.

varx = 3 + 7 * 2.

CLEAR varx. The Clear statement resets the contents of a data object to the type-related initial value.

ADD, SUBTRACT, DIVIDE and MULTIPLY statements can be used.

DATA result TYPE p DECIMALS 1 value '-5.5'.

ADD 8 TO result.

WRITE / result.

ABAP programmingChapter 3. Programming Basics


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Logical expressions

Logical expressions evaluate to true or false. In ABAP, logical expression cannot be assigned to variables

(no boolean data type). Logical expressions are used in conditional code sequences (IF, CASE).

Operator Operation

=, EQ Is equal to

, NE Is not equal to

, GT Is greater than

=, GE Is greater than or equal to



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Text Symbols

ABAP is multilingual. This means that when texts are displayed on the user interface, the logon language

of the current user is taken into account. For productive programs that should be executable with different

logon languages, the ABAP programming language provides text symbols.

Text symbols belong to a particular program and can be used in it directly. They are stored outside the

source code in their own Repository object, the text pool for the program. They can be translated into

different languages and each stored with a language indicator in the text pool.

The various texts are placed in the text pool and assigned a 3-character alphanumeric code (xxx) the

ID. 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.

For defining text symbols we can either select Goto from the menu bar, Text Elements/Text Symbols or,address the text symbol in your source code and double-click its ID(forward navigation).

To translate the text symbols of your program choose Goto/ Translation from the ABAP Editor menu.



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Text Symbols


Defining a text symbol:

Using a text symbol:

MESSAGE text-001 TYPE 'I'.

Translating a text symbol:


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Strings characters

In SAP, there are two elementary data types used for character strings: data type C and data type N.

Concatenate

REPORT ztest_dt_002bis.

DATA: init_t,

cnp(13) TYPE c,

rezultat(14) TYPE c ,

sep.

init_t = 'T'.cnp = '2711227365896'.

CONCATENATE init_t cnp INTO rezultat separated by sep.

WRITE rezultat.

ULINE.

Condense

When unwanted spaces appear, the CONDENSE statement can be used. This will remove unnecessary

spaces within a value of a variable.

DATA spaced_name(40) TYPE c VALUE 'Mrs. Dorina Birauas'.

CONDENSE spaced_name.

WRITE / spaced_name.



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Strings characters

Condense No-GAPS

CONDENSE spaced_name NO-GAPS.

Find the length of a string

DATA: spaced_name(40) TYPE c VALUE 'Mrs. Dorina Birauas',

len TYPE i.

len = strlen( spaced_name ).

WRITE / len.

Replace

DATA name(40) TYPE c VALUE 'Mrs, Dorina Birauas'.

REPLACE ',' WITH '.' INTO name.WRITE / name.



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Strings characters

Search

Two system variables are used with SEARCH: sy-subrc (which identifies if the search was successful or

not, 0 meaning succesfull) and sy-fdpos (if the search is successful is set to the position of the character

string searched for in the variable).

Example 1

DATA name(40) TYPE c VALUE 'Mrs, Dorina Birauas'.

WRITE: / 'name:', name.SKIP.SEARCH name FOR ','.

WRITE / 'searching for ","'.

WRITE: / 'sy-subrc:', sy-subrc , / 'sy-fdpos', sy-fdpos.ULINE.

Example 2

SEARCH name FOR 'B*'.

WRITE / 'searching for "B*"'.

WRITE: / 'sy-subrc:', sy-subrc , / 'sy-fdpos', sy-fdpos.

ULINE.



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Strings characters

Shift

SHIFT allows moving of the content of a character string left or right, character by character. If there are

no addition, the system will shift just one character to the left.

Example 1

DATA no_ang(10).

no_ang = '0002563'.

SHIFT no_ang LEFT DELETING LEADING '0'.

WRITE: no_ang.

Example 2

no_ang = '0002563'.

WRITE: / no_ang.

SHIFT no_ang CIRCULAR.

WRITE: / no_ang.

If CIRCULAR addition is used, everything will be moved one space to the left, but the character which is

displayed at the beginning of the statement will reappear at the end, rather than leaving a blank space.



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Strings characters

Split

DATA: name(40) TYPE c VALUE 'Mrs. Dorina Birauas',

title(4),

firstname(30),

lastname(30),

sep.

WRITE: 'Name: ', name.

SKIP.

SPLIT name AT sep INTO title firstname lastname.

WRITE: / 'Title:', title.WRITE: / 'Firstname:', firstname.

WRITE: / 'Lastname:', lastname.

Subfields

DATA: telefon(12) type c,

cod_tara(3) type c,

nrtel(10) type c.

telefon = '+40730012658'.WRITE: 'Telefon: ', telefon.

SKIP.

cod_tara = telefon(3).

nrtel = telefon+3(9).

WRITE: / 'Cod tara:', cod_tara.

WRITE: / 'Nr. telefon:', nrtel.



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Conversions


The programmer is responsible to ensure that the data types used are compatible with one another

when used for calculations or moving data to and from objects.

SAP has built in automatic data type conversions for many of the standard data types within ABAP,

sometimes the inbuilt conversions do not work.

Conversion rules are predefined logic that determine how the contents of the source field can be entered

into a target field.

Example:

MOVE var2 TO var1.

If both data objects var2 and var1 are of different types, then there is a type conflict. In this case, a type

conversion is carried out automatically, if a conversion rule exists.


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Date and time fields

Date and Time are not stored as numeric data types, but as character data types. Calculations can be

made with them because of the inbuilt automatic data type conversions.

For a date field, the data type is referred to with d,and the limit is 8 characters. The first 4 represent the

year, the next two values the month, and the final two the day. The VALUE addition is used to specify the

date and if it is not used, by default the value is assigned as eight zeros.

DATA: data_a TYPE d VALUE'20140723',

data_b LIKE sy-datum,data_c TYPE d,

time_a type t VALUE '045400',

time_b LIKE sy-uzeit.

data_b = sy-datum.

time_b = sy-uzeit.

WRITE: / 'Data 1: ', data_a,

/ 'Data 2: ', data_b,/ 'Data 3: ', data_c.

skip.

WRITE: / 'Ora 1: ', time_a.

WRITE: / 'Ora 2: ', time_b.

Sy-datum and sy-uzeit represent the system date and time.



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Calculations with date and time data type fields

Example

DATA: data_a TYPE sy-datum,

data_b LIKE sy-datum,

data_c type i,

time_a LIKE sy-uzeit,

time_b LIKE sy-uzeit,

time_c type i.

data_a = '19951001'.data_b = sy-datum.

data_c = data_b - data_a.

time_a = sy-uzeit.

time_b = 080000.

time_c = time_b - time_a.

WRITE: / 'Data angajarii: ', data_a,

/ 'Data curenta: ', data_b,

/ 'Vechimea (in zile): ', data_c.

WRITE: / 'Diferenta in secunde dintre cele 2 ore: ', time_c.

In ABAP, Currency and Quantity are treated the same as packed number fields. Currency must be

declared as data type p, and attention must be paid to the number of decimals. It is better to associate

these fields with the data types of those in a table created in the ABAP Dictionary. This is because the

ABAP dictionary will already have defined the correct field length and number of decimal places for these.



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IF statement

How the programmer structures a program using logical expressions will determine the complete flow of

the program and the sequence in which the actions are performed. IF is a control statement and allows

making decisions, resulting in a number of different outcomes based on the decisions taken.

IF logical_expression.

1 or more statements.

ENDIF.



ELSE.


ENDIF.



1 or more statements.ELSEIF logical_expression.


ENDIF.


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IF statement

Examples

REPORT ztest_dt_003bis.DATA: nume(20) TYPE c VALUE 'Pop',

salar_ian(10) TYPE p DECIMALS 2 VALUE 2050,

salar_feb(10) TYPE p DECIMALS 2 VALUE 2023.

PERFORM main.

FORM main .

IF nume = 'Pop'.

WRITE 'Castigator!'.

ENDIF.

SKIP.IF salar_ian salar_feb.

WRITE 'Salar a scazut!'.

ENDIF.

ENDFORM. " MAIN



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CASE statement

It is preferable to structure the code across multiple lines to make it more readable and make use of other

control structures if possible. The CASE structure works in a similar way to the IF statement but makesthe code more readable using one logical expression.

CASE variable.

WHEN value1.

1 or more Statements.

WHEN value2.


WHEN OTHERS.


ENDCASE.


REPORT ztest_dt_003bis.

DATA salar_ian(10) TYPE p DECIMALS 2 VALUE 2050.

PERFORM main.

FORM main .

CASE salar_ian.WHEN 2000.

WRITE 'Cel mai mic salar'.

WHEN 2023.

WRITE 'salar mediu'.

WHEN OTHERS.

WRITE 'cea mai mare valoare a salarului'.

ENDCASE.

ENDFORM.


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Looping

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

DO value TIMES.


ENDDO.

WHILE condition.


ENDWHILE.

DO.


IF abort_condition.

EXIT.

ENDIF.

ENDDO.



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Looping - Examples

DATA salar_ian(10) TYPE p DECIMALS 2 VALUE 2000.

PERFORM main.FORM main .

WRITE 'Exemplu Do...Times'.

DO 2 TIMES.

salar_ian = salar_ian + 10.

WRITE: / salar_ian.

ENDDO.

SKIP.

ULINE.

WRITE 'Exemplu While'.

WHILE salar_ian


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System fields

System fields provide the application program with information about the actual system status. Several

interesting system fields are presented below:

sy-mandtlogon client;

sy-unamelogon name of the user;

sy-langulogon language of the user;

sy-datumlocal date of the ABAP system;

sy-uzeitlocal time of the ABAP system;

sy-tcodecurrent transaction code;

sy-repidname of the current ABAP program;

sy-indexloop counter at DO and WHILE loops;

sy-subrc used with many statements, it is filled by the ABAP runtime system with the

corresponding return code to indicate whether the statement could be executed successfully. Thevalue zero means that the statement was executed successfully.



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Transaction codes creations


Transactions can be included in a role menu and in a users favorites. In order to start the program, the

transaction code can be entered in the command field.

1. In the Object Navigator, right-click the name of the package, select Create.


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2. Give it a name and enter a short description. Select

Program and selection screen (report transaction).

Select Continue button.

3. Enter the name of the program.Select SAPGUI for Windows, then click

on the SAVE button from the toolbar.


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4. Insert the name of the package.

5. Click on Save.


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6. Select Create Request, if needed.

7. Insert a short description, then click on Save.


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8. Select the code that is being created (CB1K900295,

in this case).

9. A request is being created. Click on

Continue.

10. The transaction was created.


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1. In order to add a transaction as a favorite, right click

on Favorites, then Insert transaction.

2. Insert the transaction name, then click on

Continue.

3. The transaction was added.

Adding Transactions to your personal Favorites



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Summary

In this chapter we learned how to use arithmetical operators, perform conversions between

different data types, use Date and time data type, Currency data type, build control routines (IF,CASE, LOOP, DO, WHILE), use System variables and create transaction codes.

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