上述两种实体结构皆表达了「组合／部分」关系。请再看个例子：

'ex02.bas
Imports System.ComponentModel
Imports System.Drawing
Imports System.WinForms
'----------------
Class Person
 Private p_name As String
 Private p_age As Integer
 
 Public Sub New(ByVal na As String, ByVal a As Integer)
 p_name = na
 p_age = a
 End Sub
 Public Function isEqual(ByVal obj As Person) As Integer
 Dim k As Integer = 0
 If Me.p_name = obj.p_name Then
 k = 1
 End If
 isEqual = k
 End Function
 Public Sub Show()
 Messagebox.Show(Me.p_name + ", " + str(Me.p_age))
 End Sub
End Class
'-------
Public Class Form1
 Inherits System.WinForms.Form
 
 Public Sub New()
 MyBase.New()
 Form1 = Me
 'This call is required by the Win Form Designer.
 InitializeComponent()
 'TODO: Add any initialization after the InitializeComponent() call
 End Sub
 'Form overrides dispose to clean up the component list.
 Public Overrides Sub Dispose()
 MyBase.Dispose()
 components.Dispose()
 End Sub
#Region " Windows Form Designer generated code "
.........
#End Region
 Protected Sub Form1_Click(ByVal sender As Object,
  ByVal e As System.EventArgs)
 Dim a As New Person("Alvin", 35)
 Dim b As New Person("David", 25)