Dim o() As String   
MsgBox Not Not o   
ReDim o(100)   
MsgBox Not Not o

Private Declare Function SafeArrayGetDim Lib "oleaut32.dll" (ByRef saArray() As Any) As Long   

Private Sub Form_Load()   
Dim a() As Long   
'ReDim a(0)   
If (SafeArrayGetDim(a) > 0) Then   
   Debug.Print "array as been initialized"   
Else   
   Debug.Print "array as not been initialized"   
End If   
End Sub