Imports System.Collections
public class Test
public Shared Sub Main
Dim employees As New Collection
employees.Add(New Employee("A"))
employees.Add(New Manager("B"))
employees.Add(New Employee("C"))
Dim emp As Employee
Dim employee_enumerator As IEnumerator
employee_enumerator = employees.GetEnumerator()
Do While (employee_enumerator.MoveNext)
emp = CType(employee_enumerator.Current, Employee)
Console.WriteLine(emp.Name)
Loop
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
C