| In this chapter we begin coverage of the essentials of the VB.NET language, which has undergone radical improvements from previous versions of Visual Basic. Traditionally, Visual Basic has been used as a visual development tool to create Windows programs. Later versions of Visual Basic have also made the language useful for creating COM components and other server programs without a visual interface. VB.NET brings full flexibility to Visual Basic, enabling you to use the language to create any kind of program in the .NET environment, including components, Web applications, and Web services. You can also create console programs that run locally and do not have a Windows user interface. Although normally you will use the powerful Visual Studio .NET development environment, it is also possible to build VB.NET applications using simple command-line tools. In the first part of the chapter we provide an overview of VB.NET as a visual development environment and also explain the new feature of using VB.NET to create console applications. A "Hello, world" program introduces the basic structure of VB.NET programs. We then cover variables , operators, control structures, formatting, methods , and input/output. Classes are fundamental in VB.NET, and we examine them in some detail. Besides the standard features, VB.NET adds some convenience features, such as properties. We cover the essentials of data types in VB.NET, which correspond to types in the Common Type System (CTS) used in all .NET languages. We discuss the fundamental distinction between value and reference types and see how to convert between them using boxing and unboxing operations. Although we start out slowly, orienting you to the environment and dissecting the basic structure of a VB.NET program, our pace in this chapter and in the rest of Part 2 is somewhat fast paced, as we want to quickly cover the essentials of the VB.NET language so that the rest of the book can focus on the .NET Framework classes and the different kinds of applications that can be created using these classes. For a more leisurely and complete treatment of VB.NET as a programming language, please refer to our book Introduction to Visual Basic Using .NET .  |
