How to Use RegEx for Sheet Names in Excel? - regex

Question

I'm trying to duplicate a sheet. The user inputs the sheet name with an Input Box.
I'm trying to figure out how to interrupt the process if the user inputs a sheet name that already exists.
My plan is to use RegEx to match the string against all of the sheets in the workbook, and determine if the inputted name is already in use.
Here is my current code:
Dim NewSheetName As String
SheetInput: NewSheetName = InputBox("Insert the new sheet name.")
'Ends procedure if user does not input anything.
If NewSheetName = "" Then
Exit Sub
End If
'Ends procedure if the sheet name is already in use.
Dim RegEx As Object
Set RegEx = CreateObject("VBScript.RegExp")
With RegEx
.Pattern = NewSheetName
End With
For i = 1 To Sheets.Count
If RegEx.Test(Sheet(i).Name) = False Then
MsgBox ("This name is already used on a different sheet. Please use a different name.")
GoTo SheetInput
End If
Next i
I get the message
"Compile Error: Sub or Function not defined"
with Sheet in Sheet(i).Name highlighted. I assumed the name of the sheet would be inputted into the RegEx function as a string, but this doesn't seem to be happening.

Answer 1

There are many ways to check if a sheet exists. Here is one. I am sure there may be better ones.
Public Function worksheetExists(ByVal wb As Workbook, ByVal sheetNameStr As String) As Boolean
On Error Resume Next
worksheetExists = (wb.Worksheets(sheetNameStr).Name <> "")
On Error GoTo 0
End Function
Here are a couple of ways to call this function:
If worksheetExists(ThisWorkbook, "sheetNameOne") then ...
If Not worksheetExists(ThisWorkbook, "sheetNameOne") then ...

Answer 2

Adding a call to a couple of user defined functions that are reusable, and restructuring your code to use a Do Loop instead of GoTo see the following:
Public Sub AddNewWrkSht()
Dim SheetName As String
SheetName = GetValidSheetName()
Dim NewWrkSht As Worksheet
Set NewWrkSht = ThisWorkbook.Worksheets.Add
NewWrkSht.Name = SheetName
End Sub
Private Function GetValidSheetName() As String
Dim NewSheetName As String
'keep asking the user for a valid sheet name
'until it is valid
Do
NewSheetName = InputBox("Insert the new sheet name.")
Loop Until IsValidSheetName(NewSheetName)
GetValidSheetName = NewSheetName
End Function
Private Function IsValidSheetName(ByVal SheetName As String) As Boolean
If IsValueEmpty(SheetName) Then
MsgBox "You must Provide a sheet Name."
Exit Function
End If
If WorkSheetExists(SheetName) Then
MsgBox "This name is already used on a different sheet. " & _
"Please choose a different name."
Exit Function
End If
'if we make it here without exiting, then the sheet name is valid
IsValidSheetName = True
End Function
Private Function WorkSheetExists(ByVal SheetName As String) As Boolean
On Error Resume Next
WorkSheetExists = Not ActiveWorkbook.Worksheets(SheetName) Is Nothing
End Function
Private Function IsValueEmpty(ByVal varValue As Variant) As Boolean
IsValueEmpty = (Len(RemoveAllWhiteSpace(varValue)) = 0)
End Function
Private Function RemoveAllWhiteSpace(ByRef varStringIn As Variant, _
Optional ByRef RegExpIn As Object) As String
'Create if not instantiated
If RegExpIn Is Nothing Then Set RegExpIn = CreateObject("VBScript.RegExp")
With RegExpIn
.Pattern = "\s"
.MultiLine = True
.Global = True
RemoveAllWhiteSpace = CStr(.Replace(varStringIn, vbNullString))
End With
End Function