Imports System

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''

'This Class is for Running the CODE

Public Module Run

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    Public Sub Main()

        Dim book1 as New Book("BIT3444", "Learning Visual Basic", "Jim Dickhans", 56.56D)

        Console.WriteLine(book1.GetDisplayText(" "))

    End Sub

End Module

​

''

' BASE Class Product

Public Class Product

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    Private m_Code As String

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    Private m_Description As String

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    Private m_Price As Decimal

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    Public Sub New()

    End Sub

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    Public Sub New(code As String, description As String, price As Decimal)

        Me.Code = code

        Me.Description = description

        Me.Price = price

    End Sub

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    Public Property Code As String

        Get

            Return m_Code

        End Get

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        Set(value As String)

            m_Code = value

        End Set

    End Property

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    Public Property Description As String

        Get

            Return m_Description

        End Get

​

        Set(value As String)

            m_Description = value

        End Set

    End Property

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    Public Property Price As Decimal

        Get

            Return m_Price

        End Get

​

        Set(value As Decimal)

            m_Price = value

        End Set

    End Property

​

    Public Overridable Function GetDisplayText(sep As String) As String

        Return Code & sep & Price.toString("c") & sep & Description

    End Function

End Class

​

''

' DERIVED CLASS BOOK

Public Class Book

    Inherits Product

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    Private m_Author As String

​

    Public Sub New()

    End Sub

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    Public Sub New(code As String, description As String, author As String, price As Decimal)

        MyBase.New(code, description, price)

        Me.Author = author

    End Sub

​

    Public Property Author As String

        Get

            Return m_Author

        End Get

​

        Set(value As String)

            m_Author = value

        End Set

    End Property

​

    Public Overrides Function GetDisplayText(sep As String) As String

        Return MyBase.GetDisplayText(sep) & " (" & Author & ")"

    End Function

End Class

​

''

' DERIVED CLASS SOFTWARE

Public Class Software

    Inherits Product

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    Private m_Version As String

​

    Public Sub New()

    End Sub

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    Public Sub New(code As String, description As String, version As String, price As Decimal)

        MyBase.New(code, description, price)

        Me.Version = version

    End Sub

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    Public Property Version As String

        Get

            Return m_Version

        End Get

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        Set(value As String)

            m_Version = value

        End Set

    End Property

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    Public Overrides Function GetDisplayText(sep As String) As String

        Return MyBase.GetDisplayText(sep) & ", Version " & Version

    End Function

End Class

​