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The polymorphism debate, part 2

Polymorphysm and inheritance are supported by VB.NET. In this case, it's only a matter to define a third class "Child2" where p1() method will be defined for last (NotOverridable).

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I'm not a VB.NET defender (I don't like to be labeled so ... en aras de la objetividad!), and I know many different types of programmers (C++, Smalltalk, Java, etc.) who disagree when someone calls VB object-oriented programming (OOP).

However, I read the notes on SearchVB.com's "Polymorphysm Debate." I want to express my humble opinion about the code exposed there: it's only a code design issue, as another member said.

Polymorphysm and inheritance are supported by VB.NET, no doubt; and, in this case, it's only a matter to define a third class named "Child2" where p1() method will be also defined for last (NotOverridable).

Then, in p2() method of Parent Class, taking advantage of the dynamic binding provided by VB.NET, the code will take the Child2 class method p1() (as we used Me.p1())... that's all.

Saludos!

Code:


Module MyModule
    Class Parent
        Public Overridable Sub p1()
            Console.Write("Parent.p1")
        End Sub

        Public Sub p2()
            p1()
        End Sub
    End Class

    Class Child
        Inherits Parent

        Public Overrides Sub p1()
            Console.Write("Child.p1")
            p2()
        End Sub
    End Class

    Class Child2
        Inherits Parent

        NotOverridable Overrides Sub p1()
            Console.Write("Child2.p1")
        End Sub
    End Class

    Sub Main()

        Dim p As Parent
        Dim c As Child

        p = New Parent()
        p.p1() ' "Parent.p1"
        p.p2() ' "Parent.p1"

        p = New Child()
        p.p1() ' "Child.p1"-"Child2.p1"
        p.p2() ' "Child2.p1"

        c = New Child()
        c.p1()
        c.p2()

    End Sub
End Module

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