Structure of an ABAP Program

The ABAP program contains the following components, A general overview of the ABAP program components:
Source Text
Contains the ABAP statements.

Program attributes
Contains technical settings for the program execution

Screens
Screens consists the actual screen contents and associated flow logic

User interface
the user interface consists of all the individual user interface elements. its made up of titles and the GUI statuses.

Text elements
Text elements are language specific. These text elements include selection texts, headers, text symbols and lists. All these texts can be translated

Documentation
Its also language specific, Its usually formulated from the user's perspective

Variants
they store predefined input fields on program selection screens

Complete and Incomplete Types

The ABAP standard types are divided into two, they are Complete and Incomplete datatypes. Let us look at them in detail.
Complete ABAP Standard Types:

• D - Type for date, Length 8 (fixed)
  
• T - Type for time, Length 6 (fixed)


• I - Type for integer, Length 4 (fixed)


• F - Type for floating point number, length 8 (fixed)


• STRING - Type for dynamic length character string


• XSTRING - Type for dynamic length byte sequence (HeXadecimal string)

Incomplete ABAP Standard Types:

• C - Type for character string, fixed length has to be assigned


• N - Type for numerical character string, fixed length has to be assigned


• X - Type for byte sequence, fixed length has to be assigned


• P - Type for packed number, fixed length has to be assigned (more about packed number, decimal points may also be assigned)

ABAP Language Elements - Declarative Statements

These statements are used to define data types or declare data objects in the program

TYPES :
A formal variable description is called DATA TYPES
Example code:
TYPES my_c_type(8) TYPE c.
TYPES my_n_type(5) TYPE n.

DATA:
A variable concretely defined by means of a data type is called a DATA OBJECT
Example code:
DATA:percentage1 TYPE t_percentage
number1 TYPE i value 17,
city(15)TYPE c.

Walk Through of the ABAP workbench

• ABAB Editor - For writing and editing the program code
• ABAP Dictionary - Retrieving global types and processing datetable definitions
• Menu Painter - Designing the User Interface (GUI)
• Screen Painter - Designing the screens
• Function builder - Processing functional modules
• Class Builder - For designing and processing ABAP Object class

First ABAP Program

Lets keep up the tradition and write the first "Hello World" ABAP program.
Code:
PROGRAM FIRST.
WRITE 'Hello World'.
Please keen in mind, ABAP has no formating restrictions and its not-case sensitive.

Basic ABAP Syntax with Examples

• ABAP programs are made up of individual statements.
• The first word in the statement is called a ABAP keyword.
• Each statement must end with a period.
• Statements can be intended.
  
• Can have multiple statements in a single line.

Example:

DATA wa_flight TYPE sflight.

SELECT * FROM sflight INTO wa_flight.

NEW-LINE.
WRITE:
wa_flight-carrid,
wa_flight-connid,
wa_flight-fldate.

ENDSELECT.

Introduction to ABAP!

ABAP (Advanced Business Application Programming) is a high level Language. ABAP remains the language for creating programs for the client-server R/3 Architecture. It uses Object Oriented concepts. Its easy to learn ABAP, considering one posses good programming skills, Object Oriented concepts and fairly good knowledge of Relational Database.

About NetWeaver

SAP Netweaver is SAP's integrated platform and its technical foundation for all SAP applications since SAP Business Suite. SAP NetWeaver provides the development and runtime environment for SAP applications and can be use for custom development and intergration with other applications and systems. SAP NetWeaver is built using open standards and industry de facto standards and can be extended with, and inter operate with technologies such as Sun Java EE, Microsoft .NET platform and IBM WebSphere.

NetWeaver is a single integrated platform that includes both applications and technology.The advantages of using a integrated platform are (1) More flexible, (2) Better intergration with applications, (3) built on open standards to ensure future interoperability and broad integration and (4) provided by a vendor that is finacially viable for a long term.

NetWeaver is essentially the integrated stack of SAP technology products. The SAP Web Application Server (aslo referred to as WebAS) is the runtime environment for the SAP applications. All the mySAP Business Suite solutions (SRM, CRM, SCM, PLM, ERP) run on SAP WebAS.

NetWeaver core products include:

• SAP Web Application Server
• SAP Exchange Infrastructure (XI)
• SAP NetWeaver Mobile
• SAP Business Information Warehouse
• SAP Enterprise Portal
• SAP Master Data Management
• SAP Enterprise Portal

About SAP

SAP(Systems Applications and Products in Data Processing) is the world's largest business software company and the third-largest independent software provider in terms of revenues. SAP's products focus on Enterprise Resource Planning (ERP), which it helped to pioneer. Its the world leader in ERP software. The company's latest technology platform named SAP netweaver which replaces SAP business Connector. According to the SAP website, there are over 100,600 sap installations serving more than 41,200 companies in more then 25 industries in more than 120 countries.