VBA function to convert name format - vba

Question

I want to take a name in First Last format and change it to Last, First. I know I could to this with a formula but I want to be complicated.
Please let me know if you see any red flags in my code, or suggestions for improvements.
Function LastFirst(Name_FL As String)
'This only works if there is a single space in the cell - Will Error If Spaces <> 1
Length = Len(Name_FL) 'Establishes Length of String
Spaces = Length - Len(Application.WorksheetFunction.Substitute(Name_FL, " ", "")) 'Number of spaces
If Spaces <> 1 Then
LastFirst = "#SPACES!#" 'Error Message
Else
SpaceLocation = Application.WorksheetFunction.Find(" ", Name_FL, 1) 'Location of space
Last = Right(Name_FL, Length - SpaceLocation) 'Establishes Last Name String
First = Left(Name_FL, SpaceLocation) 'Establishes First Name String
LastFirst = Application.WorksheetFunction.Proper(Last & ", " & First) 'Puts it together
End If
End Function 'Ta-da

Answer 1

You could simplify it to:
Function LastFirst(Name_FL As String) As String
If (Len(Name_FL) - Len(Replace(Name_FL, " ", ""))) > 1 Then
LastFirst = "#SPACES#"
Else
LastFirst = StrConv(Split(Name_FL, " ")(1) & ", " & Split(Name_FL, " ")(0), vbProperCase)
End If
End Function
The logic here is:
If there is more than 1 space, return the error string #SPACES#
If there is 1 space, the split the string using " " as a delimiter.
Use the second index of the Split array, add ", " and use the first index of the split array.
Use StrConv() to convert it all to proper case.
You might also want to add another check for no spaces:
If InStr(Name_FL, " ") > 0 Then
'// There is a space in the string
Else
'// There is no space in the string
End If
Which can also be tested for by slightly changing the logic of the above example:
Function LastFirst(Name_FL As String) As String
If (Len(Name_FL) - Len(Replace(Name_FL, " ", ""))) = 1 Then
LastFirst = StrConv(Split(Name_FL, " ")(1) & ", " & Split(Name_FL, " ")(0), vbProperCase)
Else
LastFirst = "#SPACES#"
End If
End Function
Further elaboration on functions:
You can see I've used some VBA functions here in place of your WorksheetFunction methods.
Len() returns the Length of a string.
Replace() does what it says on the tin - replaces a given string with another.
StrConv() Converts a String to a respective case (e.g. vbProperCase).
Split() Creates a zero-based single dimension array from a string, by Splitting it on a given delimiter.
Finally - Don't forget to specify a return value in your function header:
Function LastFirst(Name_FL As String)As String<~~ return type