Microsoft Office

Introducing Visual Basic for Applications 39
In many cases, you can refer to the same object in a number of different ways. Assume that you have a
workbook named Sales.xlsx and it’s the only workbook open. Furthermore, assume that this workbook
has one worksheet, named Summary. Your VBA code can refer to the Summary sheet in any of the following
ways:
Workbooks(“Sales.xlsx”).Worksheets(“Summary”)
Workbooks(1).Worksheets(1)
Workbooks(1).Sheets(1)
Application.ActiveWorkbook.ActiveSheet
ActiveWorkbook.ActiveSheet
ActiveSheet
The method that you use is determined by how much you know about the workspace. For example, if more
than one workbook is open, the second or third method is not reliable. If you want to work with the active
sheet (whatever it may be), any of the last three methods would work. To be absolutely sure that you’re
referring to a specific sheet on a specific workbook, the first method is your best choice.
Methods
Objects also have methods. You can think of a method as an action taken with an object. For example,
Range objects have a Clear method. The following VBA statement clears a Range, an action that is equivalent
to selecting the Range and then choosing Home ➪ Editing ➪ Clear ➪ Clear All:
Range(“A1:C12”).Clear
In VBA code, methods look like properties because they are connected to the object with a “dot.” However,
methods and properties are different concepts.
Variables
Like all programming languages, VBA enables you to work with variables. In VBA (unlike in some languages),
you don’t need to declare variables explicitly before you use them in your code (although doing so
is definitely a good practice).
If your VBA module contains an Option Explicit statement at the top of the module, then you
must declare all variables in the module. Undeclared variables will result in a compile error,
and your procedures will not run.
NOTE
In the following example, the value in cell A1 on Sheet1 is assigned to a variable named Rate:
rate = Worksheets(“Sheet1”).Range(“A1”).Value
You then can work with the variable Rate in other parts of your VBA code. Note that the variable Rate is
not a named range, which means that you can’t use it as such in a worksheet formula.
Controlling execution
VBA uses many constructs that are found in most other programming languages. These constructs are used to
control the flow of execution. This section introduces a few of the more common programming constructs.
The If-Then construct
One of the most important control structures in VBA is the If-Then construct, which gives your applications
decision-making capability. The basic syntax of the If-Then structure is as follows:
If condition Then statements [Else elsestatements]
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