Class with a property that performs validation : Property « Class Module « VB.Net Tutorial

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2. Class Module
3. Property

Module YourClassTest
   Sub Main()
      Dim obj1 As New YourClass("AAA")
      Dim obj2 As New YourClass("SSSSSSSSSSSSSSSSSSs")

      Console.WriteLine(obj1.YourName)
      Console.WriteLine(obj2.YourName)

      obj1.YourName = "asdfasdfasdfasdf"

      Console.WriteLine("obj1's course name is: " & obj1.YourName)
      Console.WriteLine("obj2's course name is: " & obj2.YourName)
   End Sub ' Main
End Module


Public Class YourClass
   Private yourNameValue As String ' course name for this YourClass

   Public Sub New(ByVal name As String)
      YourName = name ' validate and store course name
   End Sub ' New

   Public Property YourName() As String
      Get ' retrieve yourNameValue
         Return yourNameValue
      End Get

      Set(ByVal value As String) 
         If value.Length <= 5 Then ' if value has 5 or fewer characters
            yourNameValue = value ' store the course name in the object
         End If

         If value.Length > 5 Then ' if value has more than 5 characters
            yourNameValue = value.Substring(0, 5)

            Console.WriteLine("Name """ & value & """ exceeds maximum length (5).")
            Console.WriteLine("Limiting name to first 5 characters." & vbCrLf)
         End If
      End Set
   End Property ' YourName

   Public Sub DisplayMessage()
      Console.WriteLine("Welcome to " & YourName & "!")
   End Sub ' DisplayMessage
End Class

Name "SSSSSSSSSSSSSSSSSSs" exceeds maximum length (5).
Limiting name to first 5 characters.

AAA
SSSSS
Name "asdfasdfasdfasdf" exceeds maximum length (5).
Limiting name to first 5 characters.

obj1's course name is: asdfa
obj2's course name is: SSSSS