VBA - Returning array from Property Get

Question

If arrays are returned by reference, why doesn\'t the following work:

\'Class1 class module
Private v() As Double
Public Property Get Vec() As Double()
    V         


        

Answer 1

I want to suggest another nice way to do this using a Collection and a static Property without the need to use a class:

imagine you want to have the xlCVError enum as an array (or collection), e.g. to loop through it on errors and handle it based on the actual error.

The following is initialized once on access:

'from https://stackoverflow.com/a/56646199/1915920
Static Property Get XlCVErrorColl() As Collection
    Dim c As Collection  'will be already initalized after 1st access
                         'because of "Static Property" above!
    Set XlCVErrorColl = c
    If Not c Is Nothing Then Exit Property

   'initialize once:

    Set c = New Collection
    c.Add XlCVError.xlErrDiv0
    c.Add XlCVError.xlErrNA
    c.Add XlCVError.xlErrName
    c.Add XlCVError.xlErrNull
    c.Add XlCVError.xlErrNum
    c.Add XlCVError.xlErrRef
    c.Add XlCVError.xlErrValue
    Set XlCVErrorColl = c
End Property

Turning this into an array or implementing it as an array is straight forward, but collections seem to be more useful to me, with the disadvantage that their elements are not implicitely typed/(compile-time-)type checked.
So this would e.g. turn it into an (read-only) array (with the in-mem-copy-disadvantage mentioned in other answers/comments):

'from https://stackoverflow.com/a/56646199/1915920
Static Property Get XlCVErrorArr() As XlCVError()
   Dim a() As XlCVError
   XlCVErrorArr = a
   If UBound( a ) > 0 Then Exit Property

   'initialize once:

   Dim c As Collection:  Set c = XlCVErrorColl
   ReDim a(c.Count)
   Dim i As Integer:  For i = 1 To c.Count 
       a(i) = c(i)
   Next i
   XlCVErrorArr = a
End Function

So transforming the example from Clayton Ss answer into a static, modifiable module property using some array it would be:

'module (no class required)
'from https://stackoverflow.com/a/56646199/1915920

Private v() As Double

Static Property Get Vec(index As Long) As Double
    If UBound(v) < 3 Then  'initialize once:
      ReDim v(0 To 3)  'one could initialize it with anyting after here too
    end if

    Vec = v(index)
End Property

Public Property Let Vec(index As Long, MyValue As Double)
    v(index) = MyValue
End Property