Module Tester
Sub Main()
Dim circle As Circle
circle = New Circle(37, 43, 2.5) ' instantiate Circle
Console.WriteLine("X coordinate is " & circle.X & vbCrLf & _
"Y coordinate is " & circle.Y & vbCrLf & "Radius is " & _
circle.Radius)
circle.X = 2
circle.Y = 2
circle.Radius = 4.25
Console.WriteLine("The new location and radius of circle are " & _
vbCrLf & circle.ToString())
Console.WriteLine("Diameter is " & _
String.Format("{0:F}", circle.Diameter()))
Console.WriteLine("Circumference is " & _
String.Format("{0:F}", circle.Circumference()))
Console.WriteLine("Area is " & String.Format("{0:F}", circle.Area()))
End Sub ' Main
End Module
Public Class Point
Protected mX, mY As Integer
Public Sub New()
X = 0
Y = 0
End Sub ' New
Public Sub New(ByVal xValue As Integer, _
ByVal yValue As Integer)
X = xValue
Y = yValue
End Sub ' New
Public Property X() As Integer
Get
Return mX
End Get
Set(ByVal xValue As Integer)
mX = xValue ' no need for validation
End Set
End Property ' X
Public Property Y() As Integer
Get
Return mY
End Get
Set(ByVal yValue As Integer)
mY = yValue ' no need for validation
End Set
End Property ' Y
Public Overrides Function ToString() As String
Return "[" & mX & ", " & mY & "]"
End Function ' ToString
End Class
Public Class Circle
Inherits Point ' Circle Inherits from class Point
Private mRadius As Double ' Circle's radius
Public Sub New()
Radius = 0
End Sub ' New
Public Sub New(ByVal xValue As Integer, _
ByVal yValue As Integer, ByVal radiusValue As Double)
mX = xValue
mY = yValue
Radius = radiusValue
End Sub ' New
Public Property Radius() As Double
Get
Return mRadius
End Get
Set(ByVal radiusValue As Double)
If radiusValue > 0 Then
mRadius = radiusValue
End If
End Set
End Property ' Radius
Public Function Diameter() As Double
Return mRadius * 2
End Function ' Diameter
' calculate Circle circumference
Public Function Circumference() As Double
Return Math.PI * Diameter()
End Function ' Circumference
' calculate Circle area
Public Overridable Function Area() As Double
Return Math.PI * mRadius ^ 2
End Function ' Area
' return String representation of Circle
Public Overrides Function ToString() As String
Return "Center = " & "[" & mX & ", " & mY & "]" & _
"; Radius = " & mRadius
End Function ' ToString
End Class
X coordinate is 37
Y coordinate is 43
Radius is 2.5
The new location and radius of circle are
Center = [2, 2]; Radius = 4.25
Diameter is 8.50
Circumference is 26.70
Area is 56.75