Help: Question Regarding Name Function

[Dustin Schofield]

I am new to excel programming and so am using books in an effort to learn.
Up until now, I have attempted to completely understand presented code
before moving on. I have come across one example that is giving me a
difficult time, however.

It is a function that is apparently designed to run both as a worksheet
function and as a VBA callable procedure. It's purpose is to simply check
to see whether a name exists in a workbook and return a true or false
expression.

The code is as follows:


Function IsNameInWorkbook(stName As String) As Boolean

Dim X As String
Dim Rng As Range

Application.Volatile
On Error Resume Next

Set Rng = Application.Caller
Err.Clear

If Rng Is Nothing Then
X = ActiveWorkbook.Names(stName).Name
Else
X = Rng.Parent.Parent.Names(stName).Name
End If

If Err.Number = 0 Then IsNameInWorkbook = True

End Function


I follow this code for the most part but am wondering why certain elements
are necessary. My question is this: Why is a check performed to ascertain
where the function was called? Would not the code below work just as
effectively in both situations (that is - from a worksheet or VBA
procedure)?


Function IsNameInWorkbook(stName As String) As Boolean

Dim X As String

Application.Volatile
On Error Resume Next

X = ActiveWorkbook.Names(stName).Name

If Err.Number = 0 Then IsNameInWorkbook = True

End Function


Any help or thoughts would be greatly appreciated,

Thanx

Dustin

 

[Tom Ogilvy]

It should work as you suggested, but perhaps the author was trying to
illustrate some point about making the function perform in both arenas where
there would be a difference.