Implement IFormattable : IFormattable « Development « VB.Net Tutorial

1. VB.Net Tutorial
2. Development
3. IFormattable

Class YourClass
    Implements IFormattable
    Implements IComparable

    Public Value As String

    Public Overridable Overloads Function ToString(ByVal Format As String, ByVal Provider As IFormatProvider) As String Implements IFormattable.ToString
        ToString = Value
    End Function

    Public Overridable Overloads Function CompareTo(ByVal A As Object) As Integer Implements IComparable.CompareTo
        If (Value = A.Value) Then
            CompareTo = 0
        ElseIf (Value < A.Value) Then
            CompareTo = -1
        Else
            CompareTo = 1
        End If
    End Function

    Public Sub New(ByVal Value As String)
        Me.Value = Value
    End Sub
End Class

Module Module1
    Sub Main()

        Dim A As New YourClass("Hello")
        Dim B As New YourClass("Hi")

        Console.WriteLine(A)
        Console.WriteLine(B)
        Console.WriteLine(A.CompareTo(B))
    End Sub
End Module

Hello
Hi
-1