' Visual Basic 2008 9.0 .NET Examples - Containment - Object Oriented Programming : 
Class Robot
    Private m_Position As Position = New Position
    Public ReadOnly Property Position() As Position
        Get
            Position = m_Position
        End Get
    End Property
    Private m_Direction As Integer
    Public Sub Rotate()
        m_Direction += 1
        If m_Direction > 3 Then m_Direction = 0
    End Sub
    Public Sub PlaceStep()
        Select Case m_Direction
            Case 0 ' up
                Position.Y = Position.Y + 1
            Case 1 ' right
                Position.X = Position.X + 1
            Case 2 ' down
                Position.Y = Position.Y - 1
            Case 3 ' left
                Position.X = Position.X - 1
        End Select
    End Sub
End Class
Module RobotTestFixture
    Public Sub Main()
        Dim robot1 As Robot = New Robot
        Console.WriteLine(robot1.Position IsNot Nothing)
        Console.WriteLine(robot1.Position.X = 0)
        Console.WriteLine(robot1.Position.Y = 0)
        '
        robot1.PlaceStep()
        Console.WriteLine(robot1.Position IsNot Nothing)
        Console.WriteLine(robot1.Position.X = 0)
        Console.WriteLine(robot1.Position.Y = 1)
        '
        robot1.PlaceStep()
        Console.WriteLine(robot1.Position IsNot Nothing)
        Console.WriteLine(robot1.Position.X = 0)
        Console.WriteLine(robot1.Position.Y = 2)
        '
        robot1.Rotate()
        Console.WriteLine(robot1.Position IsNot Nothing)
        Console.WriteLine(robot1.Position.X = 0)
        Console.WriteLine(robot1.Position.Y = 2)
        '
        robot1.PlaceStep()
        Console.WriteLine(robot1.Position IsNot Nothing)
        Console.WriteLine(robot1.Position.X = 1)
        Console.WriteLine(robot1.Position.Y = 2)
        '
        robot1.Rotate()
        robot1.PlaceStep()
        Console.WriteLine(robot1.Position IsNot Nothing)
        Console.WriteLine(robot1.Position.X = 1)
        Console.WriteLine(robot1.Position.Y = 1)
        '
        robot1.Rotate()
        robot1.PlaceStep()
        Console.WriteLine(robot1.Position IsNot Nothing)
        Console.WriteLine(robot1.Position.X = 0)
        Console.WriteLine(robot1.Position.Y = 1)
        '
        robot1.Rotate()
        robot1.PlaceStep()
        Console.WriteLine(robot1.Position IsNot Nothing)
        Console.WriteLine(robot1.Position.X = 0)
        Console.WriteLine(robot1.Position.Y = 2)
        '
        Console.ReadLine()
    End Sub
End Module
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