VBA - Create empty array - arrays

Question

I have a function that takes an array of strings and map each string to a Date instance. The function boils down to the following code.
Private Function ParseDates(dates() As String) As Date()
Dim res() As Date
Dim i As Integer
If UBound(dates) >= 0 Then
ReDim res(UBound(dates)) As Date
End If
For i = LBound(dates) To UBound(dates)
res(i) = #01/01/2000#
Next i
ParseDates = res
End Function
The function works just fine as long as the argument dates is nonempty. When dates is empty res is not given a dimension. As a result, the returned value is not enumerable causing to users of this function to crash if the result is enumerated in a loop.
parsedDates = ParseDates(input)
For i = 1 To UBound(parsedDates) ' Suscription out of range
...
How do I instantiate and return an empty array, when dates is empty?
If you call Split("",".") you receive an object with type String(0 to -1). I need my function to return a object of type Date(0 to -1) as Date() is not an actual array.
I have tried with ReDim res(-1) this causes an Subscript out of range error.

Answer 1

This seems to do the trick:
Private Declare Function EmptyDateArray Lib "oleaut32" Alias "SafeArrayCreateVector" (Optional ByVal vt As VbVarType = vbDate, Optional ByVal lLow As Long = 0, Optional ByVal lCount As Long = 0) As Date()
Function emptyDate() as Date()
emptyDate = EmptyDateArray()
End Function
Based on an answer by user wgweto for this question at VBForums.

Answer 2

I've used something like this in the past.
Public Function IS_ARRAY_EMPTY(arrInput As Variant) As Boolean
Dim lngTemp As Long
On Error GoTo eHandle
lngTemp = UBound(arrInput)
IS_ARRAY_EMPTY = False
Exit Function
eHandle:
IS_ARRAY_EMPTY = True
End Function

Answer 3

You specifically mentioned problems in which the calling code needs to iterate over the return value and that iterating over a non-dimensioned array throws an error. Collections don't have that problem. One possibility would be to refactor your code so that it returns a collection (which might or might not have zero elements):
Private Function ParseDates(dates() As String) As Collection
Dim res As New Collection
Dim i As Long
For i = LBound(dates) To UBound(dates)
res.Add #1/1/2000#
Next i
Set ParseDates = res
End Function
Say the calling code has the line:
Set C = ParseDates(dates)
Even if C.Count = 0, the following loop works:
Dim d As Variant
For Each d In C
'process d
Next d

Answer 4

Try this:
Private Function ParseDates(dates() As String) As Date()
Dim res() As Date
Dim i As Integer
Dim k%
k=0
If UBound(dates) >= 0 Then
ReDim res(UBound(dates)) As Date
End If
For i = LBound(dates) To UBound(dates)
if dates(i)<>"" then
k=k+1
redim preserve res(k)
end if
res(k) = #01/01/2000#
Next i
if k=0 then
redim res(ubound(dates))
end if
ParseDates = res
End Function