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POVBA Arrays - test for empty, create new, return element
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copied!<p>Please would someone who understands VBA Arrays (Access 2003) help me with the following code.</p> <p>The idea is that ClassA holds a dynamic array of ClassB instances. The dynamic array starts empty. As callers call ClassA.NewB() then a new instance of ClassB is created, added to the array, and returned to the caller. The problem is that I can't return the new instance of ClassB to the caller, but get "Runtime error 91: Object variable or With block variable not set"</p> <p>Also, a little WTF occurs where UBound() fails but wrapping the exact same call in another function works!?!? (Hence MyUbound() )</p> <p>I'm from a C++ background and this VBA stuff is all a bit strange to me!</p> <p>Thanks for any help!</p> <p>Main code:</p> <pre><code>Dim a As clsClassA Dim b As clsClassB Set a = New clsClassA a.Init Set b = a.NewB(0) </code></pre> <p>clsClassA:</p> <pre><code>Option Compare Database Private a() As clsClassB Public Sub Init() Erase a End Sub Public Function NewB(i As Integer) As Variant 'If (UBound(a, 1) < i) Then ' FAILS: Runtime error 9: Subscript out of range If (MyUBound(a) < i) Then ' WORKS: Returns -1 ReDim Preserve a(0 To i) End If NewB = a(i) ' FAILS: Runtime error 91: Object variable or With block variable not set End Function Private Function MyUBound(a As Variant) As Long MyUBound = UBound(a, 1) End Function </code></pre> <p>clsClassB:</p> <pre><code>Option Compare Database ' This is just a stub class for demonstration purposes Public data As Integer </code></pre>

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