How do I declare a global variable in VBA?
The question is really about scope, as the other guy put it.
In short, consider this "module":
Public Var1 As variant 'Var1 can be used in all
'modules, class modules and userforms of
'thisworkbook and will preserve any values
'assigned to it until either the workbook
'is closed or the project is reset.
Dim Var2 As Variant 'Var2 and Var3 can be used anywhere on the
Private Var3 As Variant ''current module and will preserve any values
''they're assigned until either the workbook
''is closed or the project is reset.
Sub MySub() 'Var4 can only be used within the procedure MySub
Dim Var4 as Variant ''and will only store values until the procedure
End Sub ''ends.
Sub MyOtherSub() 'You can even declare another Var4 within a
Dim Var4 as Variant ''different procedure without generating an
End Sub ''error (only possible confusion).
You can check out this MSDN reference for more on variable declaration and this other Stack Overflow Question for more on how variables go out of scope.
Two other quick things:
- Be organized when using workbook level variables, so your code doesn't get confusing. Prefer Functions (with proper data types) or passing arguments ByRef.
- If you want a variable to preserve its value between calls, you can use the Static statement.
This is a question about scope.
If you only want the variables to last the lifetime of the function, use Dim
(short for Dimension) inside the function or sub to declare the variables:
Function AddSomeNumbers() As Integer
Dim intA As Integer
Dim intB As Integer
intA = 2
intB = 3
AddSomeNumbers = intA + intB
End Function
'intA and intB are no longer available since the function ended
A global variable (as SLaks pointed out) is declared outside of the function using the Public
keyword. This variable will be available during the life of your running application. In the case of Excel, this means the variables will be available as long as that particular Excel workbook is open.
Public intA As Integer
Private intB As Integer
Function AddSomeNumbers() As Integer
intA = 2
intB = 3
AddSomeNumbers = intA + intB
End Function
'intA and intB are still both available. However, because intA is public, '
'it can also be referenced from code in other modules. Because intB is private,'
'it will be hidden from other modules.
You can also have variables that are only accessible within a particular module (or class) by declaring them with the Private
keyword.
If you're building a big application and feel a need to use global variables, I would recommend creating a separate module just for your global variables. This should help you keep track of them in one place.
To use global variables, Insert New Module from VBA Project UI and declare variables using Global
Global iRaw As Integer
Global iColumn As Integer
You need to declare the variables outside the function:
Public iRaw As Integer
Public iColumn As Integer
Function find_results_idle()
iRaw = 1
iColumn = 1