Enumerable.Max(Of TSource) Method (IEnumerable(Of TSource))

' This class implements IComparable 
' and has a custom 'CompareTo' implementation.
Class Pet
    Implements IComparable(Of Pet)

    Public Name As String
    Public Age As Integer

    ''' <summary>
    ''' Compares Pet objects by the sum of their age and name length.
    ''' </summary>
    ''' <param name="other">The Pet to compare this Pet to.</param>
    ''' <returns>-1 if this Pet's sum is 'less' than the other Pet,
    ''' 0 if they are equal,
    ''' or 1 if this Pet's sum is 'greater' than the other Pet.</returns>
    Function CompareTo(ByVal other As Pet) As Integer _
    Implements IComparable(Of Pet).CompareTo

        If (other.Age + other.Name.Length > Me.Age + Me.Name.Length) Then
            Return -1
        ElseIf (other.Age + other.Name.Length = Me.Age + Me.Name.Length) Then
            Return 0
        Else
            Return 1
        End If
    End Function
End Class

Sub MaxEx3()
    ' Create an array of Pet objects.
    Dim pets() As Pet = {New Pet With {.Name = "Barley", .Age = 8},
                     New Pet With {.Name = "Boots", .Age = 4},
                     New Pet With {.Name = "Whiskers", .Age = 1}}

    ' Find the "maximum" pet according to the 
    ' custom CompareTo() implementation.
    Dim max As Pet = pets.Max()

    ' Display the result.
    MsgBox("The 'maximum' animal is " & max.Name)
End Sub

' This code produces the following output:
'
' The 'maximum' animal is Barley