Generic way to check if a key is in a Collection in Excel VBA

Question

I have different Collections in my code. Some hold Objects (of various kinds), others have types (like Long) within them.

Is there a way to check if a key is contain

Answer 1

The method from Robin will fail if the Collection contains objects rather than primitive types because they need to be assigned using Set and otherwise generate an error that will result in the method returning False. Here is a small adjustment:

'Test if a key is available in a collection
Public Function HasKey(coll As Collection, strKey As String) As Boolean
    On Error GoTo IsMissingError
        Dim val As Variant
'        val = coll(strKey)
        HasKey = IsObject(coll(strKey))
        HasKey = True
        On Error GoTo 0
        Exit Function
IsMissingError:
        HasKey = False
        On Error GoTo 0
End Function