Creating and Changing ABAP Programs 
ABAP programs are objects of the Repository. Like all other Repository objects (such as ABAP Dictionary tables or screens), you maintain them using an ABAP Workbench tool - in this case, the ABAP Editor.
This section provides a brief description of the ABAP Workbench and an overview of how to create and edit ABAP programs. It describes the different ways of starting the ABAP Editor. In the text below, 'open a program' always means 'start the ABAP Editor and use it to open a program'.
Starting the ABAP Editor
To start the ABAP Editor to create or change ABAP programs, NetWeaver AS ABAP offers three possibilities:
· Opening Programs in the Object Navigator
The Object Navigator of the ABAP Workbench (Transaction SE80) offers a hierarchical overview of all Repository objects, ordered by package, user name of the programmer, object types, and so on. By selecting a program, the Object Navigator supplies direct access to all components of a program, such as main program, includes, classes, or global data. By selecting a program object in the Object Navigator and calling a maintenance transaction, you directly open the appropriate tool for this object, as, for example, the ABAP Editor for the program source code or the Class Builder for classes.
This way is appropriate for all ABAP programs, as the Object Navigator gives you a constant overview of all components of a program. In particular, screens and user interfaces are displayed.
To open ABAP
programs directly from the tool ABAP Editor, select the menu path Tools
® ABAP Workbench ® Development ® ABAP Editor from the SAP menu of 
SAP Easy
Access (or start Transaction SE38). If you want to change a program using
this method, you must already know its name and environment.
This procedure is only suited for maintaining or creating relatively simple or short programs, which have few or no additional components.
In any of the tools in the ABAP Workbench, you can open a different Repository object by positioning the cursor on it and double-clicking. The system automatically opens the object using the correct tool. This also applies to editing ABAP programs.
Forward navigation by double-click can be used at any point where the names of ABAP programs appear in the ABAP Workbench.
Naming ABAP Programs
The name of an ABAP program can be between 1 and 30 characters long. The following symbols and signs must not be used in program names: Period (.), comma (,), space ( ), parentheses (), apostrophe (‘), inverted commas (“), equals sign (=), asterisk (*), accented characters or German umlauts (à, é, ø, ä, ß, and so on), percentage signs (%), or underscores (_).
Program Attributes
Like many other Repository objects, ABAP programs have attributes, which are important in determining the function of the program within NetWeaver AS ABAP. For an overview of program attributes, refer to Maintaining Program Attributes.
Source Code
ABAP source code defines the processing logic of ABAP application programs. For an introduction to writing source code, refer to Editing Programs.