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Visual Basic

Visual Basic (VB) is a programming language marketed by Microsoft. The approach for connecting the programming language proper to the graphic user interface is derived from a system called Tripod, originally developed by Alan Cooper, and further developed by Cooper and his associates under contract to Microsoft. The language itself is a descendant of BASIC. VB was first introduced by Microsoft in 1991 with the intention of making programing easier by allowing users to model visually the the user interface (and, to some extent, the code).

Table of contents
1 Language Features
2 Factors Leading to Commercial Success
3 Similar Languages
4 Visual Basic for Applications
5 Criticisms of Visual Basic
6 Older Versions of Visual Basic
7 Visual Basic and HyperCard
8 See also
9 External links

Language Features

VB is an event driven programming language centered around a forms engine that enables rapid development of graphical user interface (GUI) applications and a database object library (ADO). It is used primarily for business applications such as database front ends. A derivative of VB, VBScript, is the default language for Active Server Pages.

VB was designed to be usable by the novice programmer. Its syntax is designed to resemble the English language; it does not require the use of pointer arithmetic and it has a large library of utility objects to do everything from printing a Microsoft Word document to printing barcodes or displaying a web page. A moderately skilled programmer can quickly put together a simple web browser or word processor using components provided with Visual Basic. This use of built-in visual components and programming aids was an important factor in the acceptance of Visual Basic by programmers, and the use of visual components spread both to other programming languages and to web editors.

Factors Leading to Commercial Success

Visual Basic spawned the first commercially viable reusable component market. There are thousands of 3rd party components available for sale today from hundreds of vendors.

During the Internet boom, programmers were in great demand, and many new programmers entered the field. These new programmers helped make Visual Basic becoming one of the most common languages in commercial use. not source-code compatible with Visual Basic, but the similarity of their design environments allows Visual Basic expertise to be leveraged into these environments quickly.

Similar Languages

Some products are available for other systems that can interpret a subset of the Visual Basic language or similarly target rapid application development. These products are

Microsoft has added World Wide Web support into all of their development tools. Visual Basic .NET (VB.NET) makes VB a supported language for web application development (ASP.NET). VB.Net also provides support for web services, allowing remote functions to be called over the Internet. VB.NET compiles to MSIL (a bytecode) that needs JIT compilation the first time it is executed.

Visual Basic for Applications

Visual Basic for Applications (VBA) is built into every product in the Microsoft Office family, and also in several third-party products like Visio (now owned by Microsoft) and WordPerfect Office 2002. This has made VBA a suitable tool for writing small applications for specific purposes.

However, the ability to make VBA run automatically on opening a document - blurring the distinction between passive documents and active code - made macro viruses possible.

Criticisms of Visual Basic

VB is criticized for

Some of these problems have been addressed in later versions of VB (specifically VB.NET), although in doing so backwards compatibility has been sacrificed. The language continues to attract much criticism; it also continues to cater to a large base of users.

Older Versions of Visual Basic

Visual Basic 1.0 was released for DOS. The language itself was quite sparse, and the interface was barely graphical, using extended ASCII characters to simulate the appearance of a GUI. Visual Basic versions 2.0 through 3.0 were designed to be run within Microsoft Windows. They were 16-bit applications, and the programs produced by them were also 16-bit applications, ideally run under Windows 3.x. Visual Basic 4.0 was available as a 16-bit or a 32-bit version. The 32-bit version was more powerful, and ran on Windows 95. By version 5.0, Microsoft was releasing Visual Basic exclusively for 32-bit versions of Windows. Programmers who preferred to write 16-bit programs were pleased to find that Visual Basic 5.0 was able to import programs written in Visual Basic 4.0, and it was not difficult to convert Visual Basic 5.0 programs to be compatible with Visual Basic 4.0.

Visual Basic and HyperCard

It is interesting to compare Visual Basic with HyperCard, a programming tool developed by Bill Atkinson, Dan Winkler, and their associates at Apple Computer, Inc and released in 1987. Both HyperCard and VB initially present the user with a "drawing" environment in which UI objects can be dragged, sized, captioned, and have a set of properties edited. Both connect a set of events to fragments of code. And in both cases, the code is written in a programming language that is intended to cater to the novice and be easy to use. This is not to suggest that VB is a clone or copy of HyperCard. The relationship is more like that of C and Pascal to ALGOL: one can see certain resemblances.

Whereas it is said that VB's syntax "is designed resemble the English language," HyperCard's programming language, HyperTalk, like COBOL before it (and AppleScript after it), really does consist of syntactically valid English sentences. (Whether this actually makes it any easier to read, write, understand, or maintain than BASIC is questionable.)

The biggest difference, and the reason why VB was a breakthrough in a sense that HyperCard never was, is that VB produced applications that were virtually indistinguishable in look, feel, and general characteristics from Windows applications produced with traditional development tools. That is, it produced "real" Windows applications. HyperCard produced HyperCard stacks, not true Macintosh applications. HyperCard spawned a cottage industry of commercial "stackware." The fully commercial adventure game MYST was based on an elaborated version of HyperCard. Nevertheless, HyperCard "stacks" were always recognizable as such,

HyperCard made a big impression when it was released in 1987, but for various reasons Apple did not follow it up vigorously or develop it much beyond what it was in 1987, and eventually essentially abandoned it. Other vendors had some success with HyperCard-like products, but at this writing HyperCard is mainly of historical interest.

See also

External links