Question

I have a function that I want to call from a variety of modules. Whats the best way to do this in VB (excel).

module “SheetExists”

Function Name(SheetName As String) As Boolean
' returns TRUE if the sheet exists in the active workbook
    SheetExists = False
    On Error GoTo NoSuchSheet
    If Len(Sheets(SheetName).Name) > 0 Then
        SheetExists = True
        Exit Function
    End If
NoSuchSheet:
End Function

module “Main”

If Not SheetExists.Name("mySheet") Then
    'do this
Else
    ' else do this
End If

I DONT want to have to do this or do I??

Call SheetExists.Name("mySheet")

Is that the only way to call a function from another module? Do I have to declare it as a Public function or something?

Answer 1

No, you don’t have to do that, and you can call your function from anywhere.

Try this:

Put this code in Module1:

Sub TestSheetExists()
    If SheetExists("Sheet1") Then
        MsgBox "I exist!"
    End If
End Sub

And this in Module2:

Function SheetExists(shtName As String, Optional wb As Workbook) As Boolean
    Dim sht As Worksheet

     If wb Is Nothing Then Set wb = ThisWorkbook
     On Error Resume Next
     Set sht = wb.Sheets(shtName)
     On Error GoTo 0
     SheetExists = Not sht Is Nothing
 End Function

Obviously you can use whatever names for your modules you want.

---

EDIT: I see that calling from different modules still isn’t working for you. Follow these steps exactly to set up a test workbook that should help you understand the problem.

1. Create a new Excel workbook
2. Open the VBA Editor (Alt-F11)
3. Right-click on the project and select insert module. Repeat this 4x to get 4 modules.
4. Press F4 to open the properties window, if it isn’t already open
5. Change your module names to the following: CallMe, CallMeAgain, CallMeBack, Validation
   

6. In the Validation module, paste the following function:

   Function SheetExists(shtName As String, Optional wb As Workbook) As Boolean
       Dim sht As Worksheet
   
        If wb Is Nothing Then Set wb = ThisWorkbook
        On Error Resume Next
        Set sht = wb.Sheets(shtName)
        On Error GoTo 0
        SheetExists = Not sht Is Nothing
   End Function
   

7. Paste this sub into CallMe:

   Sub TestSheetExistsFromCallMe()
       If SheetExists("Sheet1") Then
           MsgBox "I exist, and I was called from CallMe!"
       End If
   End Sub
   

8. Paste this into CallMeBack:

   Sub TestSheetExistsFromCallMeBack()
       If SheetExists("Sheet1") Then
           MsgBox "I exist, and I was called from CallMeBack!"
       End If
   End Sub
   

9. Paste this into CallMeAgain:

   Sub TestSheetExistsFromCallMeAgain()
       If SheetExists("Sheet1") Then
           MsgBox "I exist, and I was called from CallMeAgain!"
       End If
   End Sub
   

10. Press F5 to run the code from within CallMe. You should see the following messagebox:
    

11. Run the code from any of the 3 “Call” modules and you should see the corresponding messagebox.

I got the SheetExists function from Tim Williams (https://stackoverflow.com/a/6688482/138938) and use it all the time.