Visual Basic
Programming Rules
for All Programs Submitted
Glenn Thomas
Last Updated 6/28/01

The following programming rules must be followed. For now, trust me that they make sense and will help you become better programmers.

• The first two statements in every form and module of every Visual Basic program you submit must be a comment that gives your name and, an Option Explicit statement. An example of these is:
  
  

              Rem written by Glenn Thomas
              Option Explicit
  

  The comment tells me whose program this is. The Option Explicit statement requires you to explicitly declare each and every variable you use in your program. You may not appreciate this statement. But, using it will pay big dividends as you begin to write more complex programs.

• Every program procedure and function you write must be preceded by one or more comments (Rem statements) that the explain the purpose(s) of the procedure. This will help you, me and anyone else who has to read your code.

  Commenting every procedure and function is a minimum requirement. I strongly suggest that you use additional comments within your programs to explain your logic, the meaning of identifiers, etc. Based on personal experience, this is one of the most important things you can do to help yourself write understandable programs.

  I suggest that you change the default Visual Basic configuration so that the Option Explicit statement is automatically generated for you. You can do this withe the following steps.

  • Start Visual Basic
  • Click on Tools;
  • Then on Options;
  • Select the Edit tab in the dialog box
  • Make certain Require Variable Declaration is checked; and
  • Click Okay.

  From now on, Visual Basic will generate the Option Explicit statement for you whenever you create a Form of Module.

• You must use meaningful identifier names. That means I don't want to see identifiers such as Command1, Text1, and Xyz. I do want to see identifiers such as cmdCalculateTotal, curItemPrice, and sglTaxRate. Meaningful identifiers help to make programs legible. Use them.

  In particular, I call you attention to pages 41-42 and 88-90 of the text where the authors discuss well recognized and widely adopted conventions for naming Objects and Variables. I expect you to use these same conventions in your code.

• Indent your code to reflect your program's control structures. This means the code making up a procedure should be indented. When a loop or conditional statement controls the execution of other statements, these other statements should be further indented so the control is clearly indicated. This is a recursive rule.

• Procedures and functions should be short. Usually an entire procedure or function should be so short that it can be viewed as at most 2 screens in VB's code view. If it requires more than two screens to be displayed, it is almost certainly too long and complex for someone else to understand. In fact, I'd venture a guess that you might not understand it. (This rule may be violated for good cause on extremely rare occasions. But, they must be both good and rare.)

All the rules, including the first, are meant to help you become better programmers. You must observe these rules.

Consequences of Ignoring These Rules

Any project that is submitted, which violates one or more of the above rules, will receive a score of zero. This is an absolute rule. No appeals will be listened to. No excuses will be accepted. The rules are here. You have read them and can return to them anytime. Follow them.