Classic VB - How do I check if array has been initialized?

[yrwyddfa]

Here's what I've used for a long time (I didn't know about the Merri method)

Public Type SafeArray1d
    cDims As Integer
    fFeatures As Integer
    cbElements As Long
    cLocks As Long
    pvData As Long
    cElements As Long
    lLbound As Long
End Type
 
Public Const ARRAY_NOT_INITIALISED As Long = -1
 
Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, source As Any, ByVal Length As Long)
Public Declare Function VarPtrArray Lib "msvbvm60.dll" Alias "VarPtr" (Ptr() As Any) As Long
 
 
Public Function MaxOrdinal(ppSA As Long) As Long
    
    ' Eg: n = MaxOridinal(VarPtrArray(MyArray))
    
    Dim SA As SafeArray1d
    Dim pSA As Long
 
    '***********************************************
    '* Deref ppSA. C equivalent: = pSa=*ppSA . . .
    '***********************************************
    CopyMemory pSA, ByVal ppSA, 4
    
    '*****************************************************
    '* If we have a pointer then check to see how
    '* many elements we are allowed. If the array
    '* is not dimensioned then pSA will not be valid . . .
    '*****************************************************
    If pSA Then
        CopyMemory SA, ByVal pSA, LenB(SA)
        MaxOrdinal = (SA.cElements - 1)
    Else
        MaxOrdinal = ARRAY_NOT_INITIALISED
    End If
    
End Function