Chapter 2

The Fundamentals of Writing Visual Basic Code

Chapter Objectives

Estimated time: 50 minutes

This chapter describes the fundamentals of the Visual Basic programming language. With them you'll be able to exploit all of Visual Basic's features when writing programs for Microsoft Office. Although the Visual Basic programming language is based on the same principles as most other programming languages, it's much easier to learn than most.

Quick Guide

The following table lists a common set of tasks when writing Visual Basic code.

TaskDescription
Open a new module in which you can type Visual Basic codeIn the Visual Basic Editor, on the Insert menu, click Module. This opens the Code window.
Create a Visual Basic procedure In the Code window, type Sub followed by the procedure name and press ENTER.
Add comments to code Type a single quotation mark (') followed by the comment, either on a line by itself or at the end of a line of Visual Basic code.
Declare a variable to contain a specific type of dataAt the beginning of a procedure or module, type Dim, the variable name, As, and the data type. For example: Dim iCount As Integer
Have your Visual Basic application run certain code based on a conditionUse an If…Then…Else or Select Case statement.
Declare the scope of a variable For procedure-level variables, declare the variable within the procedure. For module-level variables, declare the variable at the top of the module. For public variables, declare the variable at the top of the module using the keyword Public.
Repeat the same block of code several timesUse a For…Next, Do…Loop, or While…Wend loop structure.
Determine the length of a string variableUse the Len function.
Retrieve characters from a string variableUse the Mid$, Left$, or Right$ string variable functions
Have your code pause at a particular placeSet a breakpoint by placing the cursor in the line of code and pressing F9; or click Toggle Breakpoint on the Debug menu.
Determine the value of the variable while in break modePlace the cursor over the variable name in Code window (this displays the Data Tips window); or drag the variable name to the Watch window; or display the Locals window; or in the Immediate window, type Print and the variable name, and then press ENTER.
Run a line of code immediately Type the code in the Immediate window and press ENTER.