IComparable Interface

Defines a generalized type-specific comparison method that a value type or class implements to order or sort its instances.

Imports System.Collections
Public Class Temperature
 Implements IComparable
 ' The temperature value
 Protected temperatureF As Double
 Public Overloads Function CompareTo(ByVal obj As Object) As Integer _
 Implements IComparable.CompareTo
 If obj Is Nothing Then Return 1
 Dim otherTemperature As Temperature = TryCast(obj, Temperature)
 If otherTemperature IsNot Nothing Then
 Return Me.temperatureF.CompareTo(otherTemperature.temperatureF)
 Else
 Throw New ArgumentException("Object is not a Temperature")
 End If
 End Function
 Public Property Fahrenheit() As Double
 Get
 Return temperatureF
 End Get
 Set(ByVal Value As Double)
 Me.temperatureF = Value
 End Set
 End Property
 Public Property Celsius() As Double
 Get
 Return (temperatureF - 32) * (5 / 9)
 End Get
 Set(ByVal Value As Double)
 Me.temperatureF = (Value * 9 / 5) + 32
 End Set
 End Property
End Class
Public Module Example
 Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
 Dim temperatures(9) As Temperature
 ' Initialize random number generator.
 Dim rnd As New Random()
 ' Generate 10 temperatures between 0 and 100 randomly.
 For ctr As Integer = 1 To 10
 Dim degrees As Integer = rnd.Next(0, 100)
 Dim temp As New Temperature
 temp.Fahrenheit = degrees
 temperatures(ctr - 1) = temp
 Next
 ' Sort Array.
 Array.Sort(temperatures)
 For Each temp As Temperature In temperatures
 outputBlock.Text &= temp.Fahrenheit & vbCrLf
 Next
 End Sub
End Module
' The example displays the following output (individual
' values may vary because they are randomly generated):
' 2
' 7
' 16
' 17
' 31
' 37
' 58
' 66
' 72
' 95

using System;
using System.Collections;
public class Temperature : IComparable
{
 // The temperature value
 protected double temperatureF;
 public int CompareTo(object obj)
 {
 if (obj == null) return 1;
 Temperature otherTemperature = obj as Temperature;
 if (otherTemperature != null)
 return this.temperatureF.CompareTo(otherTemperature.temperatureF);
 else
 throw new ArgumentException("Object is not a Temperature");
 }
 public double Fahrenheit
 {
 get
 {
 return this.temperatureF;
 }
 set
 {
 this.temperatureF = value;
 }
 }
 public double Celsius
 {
 get
 {
 return (this.temperatureF - 32) * (5.0 / 9);
 }
 set
 {
 this.temperatureF = (value * 9.0 / 5) + 32;
 }
 }
}
public class Example
{
 public static void Demo(System.Windows.Controls.TextBlock outputBlock)
 {
 Temperature[] temperatures = new Temperature[10];
 // Initialize random number generator.
 Random rnd = new Random();
 // Generate 10 temperatures between 0 and 100 randomly.
 for (int ctr = 1; ctr <= 10; ctr++)
 {
 int degrees = rnd.Next(0, 100);
 Temperature temp = new Temperature();
 temp.Fahrenheit = degrees;
 temperatures[ctr - 1] = temp;
 }
 // Sort ArrayList.
 Array.Sort(temperatures);
 foreach (Temperature temp in temperatures)
 outputBlock.Text += temp.Fahrenheit + "\n";
 }
}
// The example displays the following output (individual
// values may vary because they are randomly generated):
// 2
// 7
// 16
// 17
// 31
// 37
// 58
// 66
// 72
// 95

System Namespace