Word Document Properties

Public
:
Tells VBA that it should allow other program elements to see
the affected elements
Private
: 
Tells VBA that it should hide the affected elements from other
programming elements
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Chapter 3: Writing Structured VBA Programs
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Defining the effects of scope
The best way to learn about scope is to begin working with it. You can experi-
ment with simple uses of scope to see how a change in scope affects your
programs. The most important rule is that scope only affects everything out-
side the current block. That’s right: The Lego example works here, too. (See
the earlier section “Taking the Lego Approach.”)
Making a module private by adding 
Option Private Module
at the begin-
ning of the module means that everything in that module is invisible to the
outside world. Even if the module contains a 
Public Sub
, only the other 
elements inside the module can see it — the 
Public Sub
is invisible to
everything outside the module. Likewise, when you’re declaring a 
Private
Sub
, everything within the current module can still see it, but nothing out-
side the current module can.
Listing 3-4 demonstrates some of the basic elements of scope. Other exam-
ples in the book refine this concept, but this is a good starting point.
Listing 3-4
Using Global Variables
‘ Declare a private global variable.
Private MyGlobalVariable As String
Public Sub GlobalTest()
‘ Set the value of the global variable.
MyGlobalVariable = “Hello”
‘ Display the value.
MsgBox MyGlobalVariable
‘ Call the GlobalTest2 Sub.
GlobalTest2
‘ Display the value on return from the call.
MsgBox MyGlobalVariable
End Sub
Private Sub GlobalTest2()
‘ Show that the global variable is truly global.
MsgBox MyGlobalVariable
‘ Change the value of the global variable.
MyGlobalVariable = “Goodbye”
End Sub
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