'<Klasse 1>
Public eineKlasse As Object
Public myString As String
 
Public Function showMe()
    MsgBox myString & " ich beinhalte" & vbCrLf & eineKlasse.myString
End Function

'<Klasse 2>
Public eineKlasse As Object
Public myString As String
 
Public Function showMe()
    MsgBox myString & " ich beinhalte" & vbCrLf & eineKlasse.myString
End Function

'<Form 1>
    Dim c1 As Class1
    Dim c2 As Class2
 
    Set c1 = New Class1
    Set c2 = New Class2
 
    c1.myString = "Klasse 1"
    c2.myString = "Klasse 2"
 
    Set c1.eineKlasse = c2
    Set c2.eineKlasse = c1
 
    c1.showMe
    c2.showMe

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