Question

Consider a loop where you aggregate strings into a comma separated value string:

Dim Result As String
For Each Something In Things
    If Result <> vbNullString Then
        Result = Result & ","
    End If
    Result = Result & SomeStringFunction(Something)
Next Something

That works, but what if I only want distinct strings? I’ve been using this method, but it seems very “heavy-weight”:

Dim Dict As Dictionary
Set Dict = New Dictionary
For Each Something In Things
    Dict(SomeStringFunction(Something)) = vbNullString
Next Something

Dim Result As String
Dim vKey As Variant
For Each vKey In Dict.Keys
    If Result <> vbNullString Then
        Result = Result & ","
    End If
    Result = Result & CStr(vKey)
Next vKey
Set Dict = Nothing

Answer 1

OK, dirty hack time:

Dim Result As String
Dim noDupes as New Collection
For Each Something in Things
    On Error Resume Next
    noDupes.Add Something, Something
    If Err.Number = 0 Then
         If Result <> vbNullString Then
             Result = Result & ","
         End If
         Result = Result & SomeStringFunction(Something)
    End If
    Err.Clear
Next Something