# IComparable Interfaz

## Definición

Define un método de comparación generalizado específico del tipo que implementa un tipo o una clase de valor con el fin de ordenar sus instancias.Defines a generalized type-specific comparison method that a value type or class implements to order or sort its instances.

``public interface class IComparable``
``public interface IComparable``
``````[System.Runtime.InteropServices.ComVisible(true)]
public interface IComparable``````
``type IComparable = interface``
``Public Interface IComparable``
Atributos

## Ejemplos

En el ejemplo siguiente se muestra la implementación de IComparable y el método de CompareTo necesario.The following example illustrates the implementation of IComparable and the requisite CompareTo method.

``````using namespace System;
using namespace System::Collections;

public ref class Temperature: public IComparable {
/// <summary>
/// IComparable.CompareTo implementation.
/// </summary>
protected:
// The value holder
Double m_value;

public:
virtual Int32 CompareTo( Object^ obj ) {

if (obj == nullptr) return 1;

if ( obj->GetType() == Temperature::typeid ) {
Temperature^ temp = dynamic_cast<Temperature^>(obj);

return m_value.CompareTo( temp->m_value );
}
throw gcnew ArgumentException(  "object is not a Temperature" );
}

property Double Value {
Double get() {
return m_value;
}
void set( Double value ) {
m_value = value;
}
}

property Double Celsius  {
Double get() {
return (m_value - 32) / 1.8;
}
void set( Double value ) {
m_value = (value * 1.8) + 32;
}
}
};

int main()
{
ArrayList^ temperatures = gcnew ArrayList;
// Initialize random number generator.
Random^ rnd = gcnew Random;

// Generate 10 temperatures between 0 and 100 randomly.
for (int ctr = 1; ctr <= 10; ctr++)
{
int degrees = rnd->Next(0, 100);
Temperature^ temp = gcnew Temperature;
temp->Value = degrees;
}

// Sort ArrayList.
temperatures->Sort();

for each (Temperature^ temp in temperatures)
Console::WriteLine(temp->Value);
return 0;
}
// The example displays the following output to the console (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 CompareTemperatures
{
public static void Main()
{
ArrayList temperatures = new ArrayList();
// 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;
}

// Sort ArrayList.
temperatures.Sort();

foreach (Temperature temp in temperatures)
Console.WriteLine(temp.Fahrenheit);
}
}
// The example displays the following output to the console (individual
// values may vary because they are randomly generated):
//       2
//       7
//       16
//       17
//       31
//       37
//       58
//       66
//       72
//       95
``````
``````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 CompareTemperatures
Public Sub Main()
Dim temperatures As New ArrayList
' 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
Next

' Sort ArrayList.
temperatures.Sort()

For Each temp As Temperature In temperatures
Console.WriteLine(temp.Fahrenheit)
Next
End Sub
End Module
' The example displays the following output to the console (individual
' values may vary because they are randomly generated):
'       2
'       7
'       16
'       17
'       31
'       37
'       58
'       66
'       72
'       95
``````

## Comentarios

Esta interfaz la implementan los tipos cuyos valores se pueden ordenar o ordenar.This interface is implemented by types whose values can be ordered or sorted. Requiere que los tipos que se implementan definan un solo método, CompareTo(Object), que indica si la posición de la instancia actual en el criterio de ordenación es anterior, posterior o igual que un segundo objeto del mismo tipo.It requires that implementing types define a single method, CompareTo(Object), that indicates whether the position of the current instance in the sort order is before, after, or the same as a second object of the same type. Los métodos como Array.Sort y ArrayList.Sortllaman automáticamente a la implementación de IComparable de la instancia.The instance's IComparable implementation is called automatically by methods such as Array.Sort and ArrayList.Sort.

La implementación del método CompareTo(Object) debe devolver una Int32 que tenga uno de tres valores, como se muestra en la tabla siguiente.The implementation of the CompareTo(Object) method must return an Int32 that has one of three values, as shown in the following table.

Menor que ceroLess than zero La instancia actual precede al objeto especificado por el método CompareTo en el criterio de ordenación.The current instance precedes the object specified by the CompareTo method in the sort order.
CeroZero Esta instancia actual se produce en la misma posición en el criterio de ordenación que el objeto especificado por el método CompareTo.This current instance occurs in the same position in the sort order as the object specified by the CompareTo method.
Mayor que ceroGreater than zero Esta instancia actual sigue el objeto especificado por el método CompareTo en el criterio de ordenación.This current instance follows the object specified by the CompareTo method in the sort order.

Todos los tipos numéricos (como Int32 y Double) implementan IComparable, como String, Chary DateTime.All numeric types (such as Int32 and Double) implement IComparable, as do String, Char, and DateTime. Los tipos personalizados también deben proporcionar su propia implementación de IComparable para permitir el orden o la ordenación de las instancias de objeto.Custom types should also provide their own implementation of IComparable to enable object instances to be ordered or sorted.

## Métodos

 Compara la instancia actual con otro objeto del mismo tipo y devuelve un entero que indica si la posición de la instancia actual es anterior, posterior o igual que la del otro objeto en el criterio de ordenación.Compares the current instance with another object of the same type and returns an integer that indicates whether the current instance precedes, follows, or occurs in the same position in the sort order as the other object.