Visual Basic

The four colored boxes is the logo of VBA, and the two drums above them symbolize database connectivity.

Visual Basic (VB) is a third-generation event driven programming language and associated development environment from Microsoft for its COM programming model. It has one of the largest user bases In business programming. Visual Basic currently competes with C++, C# and Java for dominance in the business world, with JavaScript being another of its competitor. The final release of Visual Basic was version 6 in 1998, with Microsoft extended support ending in 2008. The designated successor is Visual Basic .NET.

2.   Visual Basic was derived from BASIC and enables:

• the rapid application development (RAD) of graphical user interface (GUI) applications;
• access to databases using DAO, RDO, or ADO; and
• the creation of ActiveX controls and objects.

VB 1.0 was introduced in 1991. The approach for connecting BASIC to the graphical user interface is derived from a prototype developed by Alan Cooper called Tripod. Microsoft contracted with Cooper and his associates to develop Tripod into a programmable shell for Windows 3.0, under the code name Ruby (no relation to the Ruby programming language). Ruby's extensible controls later became the VBX interface.

3.   Visual Basic was designed to be easy to learn and use. A programmer can put together an application using the components provided with Visual Basic itself. Programming in VB is a combination of:

• visually arranging components or controls on a form;
• specifying attributes and actions of those components; and
• writing additional lines of code for more functionality.

Although programs can be compiled into native code executables from version 5 onwards, they still require the presence of runtime libraries of approximately 2 MB in size. This runtime is included in Windows 2000 and later, but for earlier versions of Windows, it must be distributed together with the executable.

4.   Visual Basic can create executables (EXE files), ActiveX controls, and DLL files, but is primarily used to develop Windows applications and to interface web database systems. Controls provide the basic functionality of the application, while programmers can insert additional logic within the appropriate event handlers. A Visual Basic component can have no user interface, and instead provide ActiveX objects to other programs via Component Object Model (COM). This allows for server-side processing or an add-in module.

5.   Visual Basic is garbage collected using reference counting, has a large library of utility objects, and has basic object oriented support. Since the more common components are included in the default project template, the programmer seldom needs to specify additional libraries. Unlike many other programming languages, Visual Basic is generally not case sensitive. String comparisons, however, are case sensitive by default, but can be made case insensitive if so desired. The Visual Basic compiler is shared with other Visual Studio languages (C, C++), but restrictions in the Integrated development environment (IDE) do not allow the creation of some targets (Windows model DLL's) and threading models.

6.   Microsoft has developed derivatives of Visual Basic for use in scripting. Examples include Visual Basic for Applications (VBA), VBScript, and Visual Basic .NET.  more... at Wikipedia