Part I : Introduction

About VISUAL BASIC 6

Visual Basic 6 is not your grandfather's BASIC! If your knowledge of programming is limited to the QBASIC you toyed with in high school, you'll think you've landed on a different planet. You may still see the occasional GoTo hanging around but, for the most part you will be in unfamiliar territory. For one thing, the word Basic in Visual Basic is not an acronym anymore. It used to be. When the language was invented in the early 70's, BASIC stood for Beginners' All-purpose Symbolic Instruction Code, thus the acronym (word formed from the first letter of several words, in upper-case). It is certainly not just for beginners, and although it is quite versatile, I don't know if I'd call it exactly All-purpose. And while it is still Instruction Code, it is more than Symbolic now. But THE big difference is the Visual aspect of it where you work with windows and icons and pictures and multimedia. 

Visual basic is a high level programming language developed from the earlier DOS version called BASIC. Though, Visual Basic .NET is the latest technology introduced by Microsoft with tons of new features including the .NET framework and educational institues, Universities and Software Development companies have migrated to VB .NET, Visual Basic 6 is still widely learned and taught.

Learning Visual Basic 6 is quite easier than other programming languages such as C++, C#, Java etc. This is because Visual Basic enables you to work in a graphical user interface where you can just drag and drop controls that you want to work with where you have to write bunches of code to create in C++ or C# or even in Java. If you are new to programming and want to start it in the smoothest and easiest way, then you should start it with Visual Basic.

Before you start developing a Visual Basic 6 application you should be aware that some programming knowledge is useful. If you have used BASIC or Pascal or C before you got here, that's OK. If you did learn one of those languages, you were working in a procedural fashion: when you type RUN the program starts at the beginning and basically follows the instructions going down the list, skipping here and there according to control instructions until it finds some kind of END statement. That is not how Visual Basic operates. Rather than procedural it is event-driven. There will be more on that subject in the next lesson.

However, you do have to write Visual basic 6 code to program the events - there are loops and conditions and arrays. We will not be covering the fundamentals of programming as such - you should be familiar with the basic constructs such as the IF...THEN...ELSE or the FOR...NEXT statements.

versions

You may be aware that there are several dialects of the Visual Basic language in use. This tutorial is on standard Visual Basic. It uses the VB IDE (Integrated Development Environment) to let you create standalone Visual Basic applications that can be distributed as .EXE files. Visual Basic for Applications (VBA) is the language used to tie Microsoft Office products together. It links Word and Excel applications, for example. Although it is very similar to standard VB, it does have several particular techniques that must be learned on their own. VBScript is a small subset of Visual Basic, with limited instructions, mostly used in Internet applications.

As for version, this tutorial is based upon Visual Basic 6.0. You may have access to version 4 or 5 in your environment. Don't worry about it. Of course Mr. Gates would like us to rush out to the store and buy the latest release as soon as it hits the shelves but we are not all as, shall we say, fortunate, as Mr. Gates when it comes to spending money. Right now, when a new version is announced, most of the improvements cover Internet access or Class libraries, etc. At this level of training, we will not be using most of those facilities and so, one version is just about as good as another. A form is a form and a button is a button. There may be slight differences in the interface between versions but those will not matter much.

The only problems occur when you try to run an application on a lower version of the software. It normally doesn't work. But the hardest part of creating an application is usually in writing the code. Some scripts can run into the 100's of line. Fortunately the script is just text and you can work around the version problem with Cut and Paste operations. You will have to redraw the forms, buttons and so on but, that is a minor inconvenience when you can paste in the code for all those objects.

In order to be as accessible as possible, the code downloads at the end of the tutorial will all be in the form of text files that can be pasted into any version of VB.

Visual Basic .NET is now available. Although very similar in most ways to Visual Basic 6, Visual Basic .NET does have significant differences in its approach. For one thing, VB .NET is now completely object-oriented, which isn't the case with Visual Basic 6. An application that runs well in VB 6 will have to be converted, using a conversion wizard to run on VB .NET. Microsoft tell us that the conversion wizard will convert 95% of the code (an optimistic estimate?). Regardless, that leaves at least 5% that will have to be converted manually. That means that a lot of people will wait to see further improvements before jumping to the new version. And add to that the fact that Visual Studio .NET, the parent framework for VB has a huge infrastructure. It requires lots of system resources. For example, you need at least 128 meg of RAM. Excuse me! When I look at the real world I see thousands upon thousands of perfectly good computers with less than 128 meg of memory.

However, if you are just getting into programming or into VB, the basic stuff doesn't change. You still need to know how to create a form, how to put controls on a form, how to write a loop or a decision structure. That hasn't changed in ages and that you can still learn with Visual Basic 6. I see installations out in the real world still doing tons of interesting work with versions 4 or 5 of Visual Basic!