Imports System
Class Point
Inherits Object
Protected x, y As Integer
Public Sub New()
Me.x = 0
Me.y = 0
End Sub 'New
Public Sub New(ByVal X As Integer, ByVal Y As Integer)
Me.x = X
Me.y = Y
End Sub 'New
Public Overrides Function Equals(ByVal obj As Object) As Boolean
If obj Is Nothing OrElse Not [GetType]().Equals(obj.GetType()) Then
Return False
End If
Dim p As Point = CType(obj, Point)
Return x = p.x AndAlso y = p.y
End Function 'Equals
Public Overrides Function GetHashCode() As Integer
Return x ^ y
End Function 'GetHashCode
End Class 'Point
Class Point3D
Inherits Point
Private z As Integer
Public Sub New(ByVal X As Integer, ByVal Y As Integer, ByVal Z As Integer)
Me.x = X
Me.y = Y
Me.z = Z
End Sub 'New
Public Overrides Function Equals(ByVal obj As Object) As Boolean
Return MyBase.Equals(obj) AndAlso z = CType(obj, Point3D).z
End Function 'Equals
Public Overrides Function GetHashCode() As Integer
Return MyBase.GetHashCode() ^ z
End Function 'GetHashCode
End Class 'Point3D
Class [MyClass]
Public Shared Sub Main()
Dim point2D As New Point(5, 5)
Dim point3Da As New Point3D(5, 5, 2)
Dim point3Db As New Point3D(5, 5, 2)
If Not point2D.Equals(point3Da) Then
Console.WriteLine("point2D does not equal point3Da.")
End If
If Not point3Db.Equals(point2D) Then
Console.WriteLine("Likewise, point3Db does not equal point2D.")
End If
If point3Da.Equals(point3Db) Then
Console.WriteLine("However, point3Da equals point3Db.")
End If
End Sub 'Main
End Class '[MyClass]