Use For Each for Class Hierarchy : Class Inheritance « Class Module « VB.Net Tutorial

1. VB.Net Tutorial
2. Class Module
3. Class Inheritance

public class Test
   public Shared Sub Main
        Dim people As New Collection
        people.Add(New Employee("A"))
        people.Add(New Customer("B"))

        For Each person As Object In people
            Console.WriteLine(person.Name)
        Next person
   End Sub

End class


Public Class Employee
    Public Name As String

    Public Sub New(ByVal new_name As String)
        Name = new_name
    End Sub

    Public Overridable Function IsManager() As Boolean
        Return False
    End Function
End Class

Public Class Customer
    Public Name As String

    Public Sub New(ByVal new_name As String)
        Name = new_name
    End Sub
End Class

Public Class Manager
    Inherits Employee

    Public Sub New(ByVal new_name As String)
        MyBase.new(new_name)
    End Sub
    Public Overrides Function IsManager() As Boolean
        Return True
    End Function
End Class

A
B