Find length of byte array

Traditional method: To find the length of an existing byte array:

nLen = UBound(abData) - LBound(abData) + 1

Be careful, as this will cause a run-time error if abData() has not been ReDim'd.

Dim ab() As Byte
Debug.Print cnvBytesLen(ab) ' Expecting 0
ReDim ab(10)    ' NB actually 11 elements (0..10)
Debug.Print cnvBytesLen(ab) ' 11