There is no fixed set of prerequisites to learn SAP ABAP. However, having some technical knowledge makes it easier to learn this programming language.
ABAP programs are stored in the SAP database in source code and generated code. The source code can be viewed and edited using ABAP Workbench tools, while the generated code is a binary representation similar to Java bytecode.
Basics of ABAP
SAP ABAP programming (originally Allgemeiner Berichts-Aufbereitungs-Prozessor) is the fourth-generation programming language to develop business logic in SAP systems. It is written using the ABAP Workbench tool and stored in the SAP database in source code and generated code.
ABAP is the first programming language to introduce the concept of object-oriented design. It allows programmers to create software applications based on real-life business objects. These are then combined in a software model that implements the desired functionality.
ABAP enables the development of programs in several ways, including function groups, which are libraries of self-contained functions; object classes, similar to Java interfaces; and data types, defined as sets of attributes. All ABAP programs are executed within the ABAP runtime environment, which handles communication with the underlying database.
Variables
Variables are the building blocks of ABAP code. They define a program’s data structures and control its flow of operations. Variables can store both internal and external data and control and debug information.
The ABAP runtime environment uses ABAP variables to execute ABAP statements. ABAP variable types are defined in the ABAP dictionary. ABAP has three types of variables: object reference variables, data reference variables, and ABAP global variables.
ABAP also supports object-oriented programming through its class and method objects. In addition, it follows classic OOP design principles such as low coupling and high cohesion.
Data Types
ABAP is an object-oriented programming language, which means that it uses objects to represent different data types. It also supports a variety of tools, such as the ABAP Workbench, that help developers create SAP applications.
Typically, these applications consist of various tables. Generally, there is a 1-to-1 relationship between the definition of the table in the SAP dictionary and the physical table in the underlying relational database. There are also “pooled” tables, which exist at the dictionary level but are consolidated into large physical tables in the database.
ABAP programs run within the ABAP Runtime Environment, part of the SAP kernel. The runtime environment is responsible for processing ABAP statements and handling events. This environment is comparable to the Java virtual machine, or JVM.
Objects
ABAP programmers use objects to write and view ABAP code. They are also used to implement functions, control flow logic, and respond to events. Objects are stored in ABAP’s runtime system, part of the SAP kernel.
Since ABAP released 4.6C – the most recent language version – ABAP has supported object-oriented programming. It allows ABAP programs to be modularized and simplifies application development.
ABAP classes define set methods that any class implementing the interface must provide; and method pools, which contain “empty” methods. ABAP also uses object-oriented techniques, such as search helps and lock objects, to help with database processing.
Functions
ABAP supports object-oriented programming and has been SAP’s primary programming language since 1992. ABAP OO allows source code to be encapsulated into clear, reusable modules of statements called function modules, greatly simplifying development. It also improves application performance by reducing unnecessary database queries and concurrent accesses.
Function modules hide ABAP interface definitions from the programmer and provide a convenient method for accessing data. They support a variety of parameters, including default values. They can also test programs without including them in the source code.
Indexes provide accelerated access to table data for often-used selection conditions. They can be applied to tables, views, and structures. They can be sorted, grouped, and searched. They are especially helpful for analyzing complex data sets in reports.
Statements
The ABAP programming language supports multiple types of statements. These include arithmetic and logic functions, control statements, function modules, and screen- and report-editing commands. The statement SET CONTEXT determines the context in which a function is executed, while the CALL METHODS statement invokes a specific method within a module.
ABAP also includes a universal dictionary of data structure definitions available to all programs in a system. Its change and transport system tracks changes to development objects and provides tools for promoting them from the developer’s environment to the quality assurance and production systems.
In addition, ABAP supports the logical unit of work (LUW) concept. This enables developers to process large amounts of data in memory on the application server rather than sending it to the database for processing.
Variations
Many companies use the ABAP programming language to develop applications that help in software development, financial accounting, data analysis, HR management, etc. As a result, there is a constant need for people who know how to write SAP ABAP programs.
One of the most important aspects of ABAP is the dictionary, which contains all of the metadata about the system.