Find length of byte array.
Public Function cnvBytesLen ( _ ab() As Byte _ ) As Long
Dim ab() As Byte Debug.Print cnvBytesLen(ab) ' Expecting 0 ReDim ab(10) ' NB actually 11 elements (0..10) Debug.Print cnvBytesLen(ab) ' 11 ab = vbNullString ' Set to empty array Debug.Print cnvBytesLen(ab) ' 0