Visual Basic .NET has many new and improved language features — such as inheritance, interfaces, and overloading that make it a powerful objectoriented programming language. As a Visual Basic developer, you can now create multithreaded, scalable applications using explicit multithreading. Other new language features in Visual Basic .NET include structured exception handling, custom attributes, and common language specification (CLS) compliance .
The CLS is a set of rules that standardizes such things as data types and how objects are exposed and interoperate. Visual Basic .NET adds several features that take advantage of the CLS. Any CLScompliant language can use the classes, objects, and components you create in Visual Basic .NET. And you, as a Visual Basic user, can access classes, components, and objects from other CLScompliant programming languages without worrying about languagespecific
differences such as data types.
CLS features used by Visual Basic .NET programs include assemblies, namespaces, and attributes.
These are the new features to be stated briefly:
Inheritance :
Visual Basic .NET supports inheritance by allowing you to define classes that serve as the basis for derived classes. Derived classes inherit and can extend the properties and methods of the base class. They can also override inherited methods with new implementations. All classes created with Visual Basic .NET are inheritable by default. Because the forms you design are really classes, you can use inheritance to define new forms based on existing ones.
Exception Handling :
Visual Basic .NET supports structured exception handling, using an enhanced version of the Try...Catch...Finally syntax supported by other languages such as C++. Structured exception handling combines a modern control structure (similar to Select Case or While) with exceptions, protected blocks of code, and filters. Structured exception handling makes it easy to create and maintain programs with robust, comprehensive error handlers.
Overloading :
Overloading is the ability to define properties, methods, or procedures that have the same name but use different data types. Overloaded procedures allow you to provide as many implementations as necessary to handle different kinds of data, while giving the appearance of a single, versatile procedure. Overriding Properties and Methods The Overrides keyword allows derived objects to override characteristics inherited from parent objects. Overridden members have the same arguments as the members inherited from the base class, but different implementations. A member's new implementation can call the original implementation in the parent class by preceding the member name with MyBase.
Constructors and Destructors :
Constructors are procedures that control initialization of new instances of a class. Conversely, destructors are methods that free system resources when a class leaves scope or is set to Nothing. Visual Basic .NET supports constructors and destructors using the Sub New and Sub Finalize procedures.
