Microsoft Access 2010 Bible

Chapter 11: Mastering VBA Data Types and Procedures . . . . . . . . . . . . .

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Using Variables

One of the most powerful concepts in programming is the variable. A variable is a temporary stor-

age location for some value and is given a name. You can use a variable to store the result of a cal-

culation, hold a value entered by the user, or read from a table, or you can create a variable to

make a control’s value available to another procedure.

To refer to the result of an expression, you use a variable’s name to store the result. To assign an

expression’s result to a variable, you use the = operator. Here are some examples of expressions

that assign values to variables:

counter = 1

counter = counter + 1

today = Date()

Figure 11.5 shows a simple procedure using several different variables. Although this is a very sim-

ple example of using variables, it effectively demonstrates just about everything you need to know

about using VBA variables:

FIGURE 11.5

Variable declarations appear at the top of VBA procedures.

l The Dim keyword establishes the new variables — strDocName and strCriteria —

within a procedure.