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Visual BasicVisual Basic
Dennis O. Owen,Purdue UniversityIntroduction 608
Visual Basic—The Language 608
The Evolution of Visual Basic 608
Visual Basic as a Structured Language 609
Visual Basic as an Application Development
Tool 609
Object-Oriented Programming and Visual Basic 609
Visual Programming and Visual Basic 610
Event-Driven Programming in Visual Basic 610
The Visual Basic User Interface 610
Getting Started in the Visual Basic
Development Environment 610
Creating a Program in the Visual Basic
Integrated Development Environment 612
Program Development and Debugging 613
Visual Basic Language Elements 614Variables 614
Control Structures 615
Common Controls 615
Modularity: Functions and Procedures 616
Data Access 616
Files 616
Database and Data Access 616
Visual Basic.NET—Visual Basic for Internet
Applications 617
The .NET Framework 617
Visual Basic.NET 618
Conclusion 619
Glossary 619
Cross References 619
References 619INTRODUCTION
The information systems industry has been profoundly
impacted by the Internet. The Internet is an expansive
wide area network, one that is more far-reaching that any-
thing that could be constructed by a single organization,
or even a group of organizations working collaboratively.
A plethora of software is available to manage information
and communicate on the Internet. In the true spirit of
capitalism, this software has become sophisticated, fast,
and relatively inexpensive. This combination of power-
ful, inexpensive data management software and expansive
wide area networking is something business and industry
must seriously consider as a viable information distribu-
tion system.
As Internet technologies are adopted in business infor-
mation systems, it is necessary to supplement the avail-
able software with equally powerful applications that ad-
dress unique data management needs within a business.
Development of these applications requires a tool that
facilitates development, testing, and deployment with a
minimum investment of time. Visual Basic, by Microsoft,
is such a tool. Visual Basic provides a visual user inter-
face to speed application design. The integrated develop-
ment environment (IDE) provides many powerful debug-
ging tools to speed development and testing. Visual Basic
provides a set of commonly used controls that can eas-
ily be incorporated into applications. Finally, Visual Basic
provides a complete set of utilities for easy packaging and
deployment of new applications. The latest release, Visual
Basic.NET, supports Microsoft’s new .NET initiative. This
seamless integration of the application development envi-
ronment into the Internet’s basic information-sharing and
communications framework makes Visual Basic an ex-
cellent choice for Internet technologies application devel-
opment. Currently, over three million developers world-
wide use Visual Basic to create applications and othersoftware components (Shelly, Cashman, Repede, & Mick,
1999).VISUAL BASIC—THE LANGUAGE
The Evolution of Visual Basic
Visual Basic traces its roots back some 40 years to the
BASIC programming language developed by Dartmouth
College professors John Kemeny and Thomas Kurtz.
BASIC was originally intended as an instructional lan-
guage. The 1970s brought a general decrease in computer
costs and a corresponding increase in college computer
courses. BASIC, recognized for its wide range of features,
became a favorite of students. Upon graduation, these stu-
dents carried BASIC into business and industry.
Business and commercial users of BASIC soon found
that the original Dartmouth specification lacked certain
desirable features. Among these were text editing, printed
output formatting, and file handling. BASIC vendors be-
gan to add to the original Dartmouth specifications to ad-
dress these shortfalls. The addition of these extensions
began the evolution toward today’s Visual Basic (Hare,
1982). Currently, the most widely used version of Visual
Basic is 6.0. Microsoft recently released a new version
of Visual Basic, Visual Basic.NET, which incorporates its
new .NET Internet technologies. Visual Basic.NET and its
relationship to Visual Basic and Internet programming
will be covered later. Visual Basic comes in several differ-
ent editions designed to meet the needs of specific classes
of users. The Learning Edition is a student version of
Visual Basic that supports the language elements neces-
sary for development of simple Visual Basic programs like
those used in college-level course work. Anyone planning
to use Visual Basic for commercial or professional appli-
cations development should use either the Professional
Edition or the Enterprise Edition. These editions support608