Binaryworld - InstrRev - Backward Instr for VB4 and VB5 ... [ VB -> String ]

' A clone of VB6's InstrRev function (including its quirks)
' that works under VB4 and VB5

Function InstrRev(StringCheck As String, StringMatch As String, _
  Optional Start As Long = -1, Optional Compare As VbCompareMethod = _
  vbBinaryCompare) As Long

  Dim index As Long
  Dim lastIndex As Long

  If Start > Len(StringCheck) Then
    ' this is probably a quirk in VB6's InstrRev function: when
    ' start is higher than the source string length, the function
    ' returns zero
    Exit Function
  ElseIf Start < 0 Then
    ' if Start is omitted, last valid index is the end of string
    lastIndex = Len(StringCheck)
  Else
    ' else, we must account for the length of the searched string
    ' (this is the way VB6's InstrRev function works)
    lastIndex = Start + 1 - Len(StringMatch)
  End If

  Do
    index = InStr(index + 1, StringCheck, StringMatch, Compare)
    ' exit if not found, or if it's past the start index
    If index = 0 Or index > lastIndex Then Exit Do
    ' remember the index we've just found
    InstrRev = index
  Loop

End Function