Object.Equals Método

Source:

Object.cs

Source:

Object.cs

Source:

Object.cs

public:
 virtual bool Equals(System::Object ^ obj);

public virtual bool Equals (object obj);

public virtual bool Equals (object? obj);

abstract member Equals : obj -> bool
override this.Equals : obj -> bool

Public Overridable Function Equals (obj As Object) As Boolean

Parámetros

Devoluciones

true si el objeto especificado es igual al objeto actual; en caso contrario, false.

Comentarios

Para obtener más información sobre esta API, consulte Comentarios complementarios de la API para Object.Equals.

Consulte también

• ReferenceEquals(Object, Object)
• GetHashCode()
• ValueType
• IComparable
• ArrayList
• Hashtable

Source:

Object.cs

Source:

Object.cs

Source:

Object.cs

public:
 static bool Equals(System::Object ^ objA, System::Object ^ objB);

public static bool Equals (object objA, object objB);

public static bool Equals (object? objA, object? objB);

static member Equals : obj * obj -> bool

Public Shared Function Equals (objA As Object, objB As Object) As Boolean

Parámetros

Devoluciones

Es true si los dos objetos se consideran iguales; en caso contrario, es false. Si tanto objA como objB son null, el método devuelve true.

Ejemplos

En el ejemplo siguiente se muestra el Equals(Object, Object) método y se compara con el ReferenceEquals método .

using System;

public class Example
{
   public static void Main()
   {
      Dog m1 = new Dog("Alaskan Malamute");
      Dog m2 = new Dog("Alaskan Malamute");
      Dog g1 = new Dog("Great Pyrenees");
      Dog g2 = g1;
      Dog d1 = new Dog("Dalmation");
      Dog n1 = null;
      Dog n2 = null;

      Console.WriteLine("null = null: {0}", Object.Equals(n1, n2));
      Console.WriteLine("null Reference Equals null: {0}\n", Object.ReferenceEquals(n1, n2));

      Console.WriteLine("{0} = {1}: {2}", g1, g2, Object.Equals(g1, g2));
      Console.WriteLine("{0} Reference Equals {1}: {2}\n", g1, g2, Object.ReferenceEquals(g1, g2));

      Console.WriteLine("{0} = {1}: {2}", m1, m2, Object.Equals(m1, m2));
      Console.WriteLine("{0} Reference Equals {1}: {2}\n", m1, m2, Object.ReferenceEquals(m1, m2));

      Console.WriteLine("{0} = {1}: {2}", m1, d1, Object.Equals(m1, d1));
      Console.WriteLine("{0} Reference Equals {1}: {2}", m1, d1, Object.ReferenceEquals(m1, d1));
   }
}

public class Dog
{
   // Public field.
   public string Breed;

   // Class constructor.
   public Dog(string dogBreed)
   {
      this.Breed = dogBreed;
   }

   public override bool Equals(Object obj)
   {
      if (obj == null || !(obj is Dog))
         return false;
      else
         return this.Breed == ((Dog) obj).Breed;
   }

   public override int GetHashCode()
   {
      return this.Breed.GetHashCode();
   }

   public override string ToString()
   {
      return this.Breed;
   }
}
// The example displays the following output:
//       null = null: True
//       null Reference Equals null: True
//
//       Great Pyrenees = Great Pyrenees: True
//       Great Pyrenees Reference Equals Great Pyrenees: True
//
//       Alaskan Malamute = Alaskan Malamute: True
//       Alaskan Malamute Reference Equals Alaskan Malamute: False
//
//       Alaskan Malamute = Dalmation: False
//       Alaskan Malamute Reference Equals Dalmation: False

open System

// Class constructor
type Dog(dogBreed) =
    // Public property.
    member _.Breed = dogBreed

    override this.Equals(obj) =
        match obj with
        | :? Dog as dog when dog.Breed = this.Breed -> true
        | _ -> false

    override _.GetHashCode() =
        dogBreed.GetHashCode()

    override _.ToString() =
        dogBreed

let m1 = Dog "Alaskan Malamute"
let m2 = Dog "Alaskan Malamute"
let g1 = Dog "Great Pyrenees"
let g2 = g1
let d1 = Dog "Dalmation"
let n1 = Unchecked.defaultof<Dog>
let n2 = Unchecked.defaultof<Dog>

printfn $"null = null: {Object.Equals(n1, n2)}"
printfn $"null Reference Equals null: {Object.ReferenceEquals(n1, n2)}\n"

printfn $"{g1} = {g2}: {Object.Equals(g1, g2)}"
printfn $"{g1} Reference Equals {g2}: {Object.ReferenceEquals(g1, g2)}\n"

printfn $"{m1} = {m2}: {Object.Equals(m1, m2)}"
printfn $"{m1} Reference Equals {m2}: {Object.ReferenceEquals(m1, m2)}\n"

printfn $"{m1} = {d1}: {Object.Equals(m1, d1)}"
printfn $"{m1} Reference Equals {d1}: {Object.ReferenceEquals(m1, d1)}"

// The example displays the following output:
//       null = null: True
//       null Reference Equals null: True
//
//       Great Pyrenees = Great Pyrenees: True
//       Great Pyrenees Reference Equals Great Pyrenees: True
//
//       Alaskan Malamute = Alaskan Malamute: True
//       Alaskan Malamute Reference Equals Alaskan Malamute: False
//
//       Alaskan Malamute = Dalmation: False
//       Alaskan Malamute Reference Equals Dalmation: False

Module Example
   Public Sub Main()
      Dim m1 As New Dog("Alaskan Malamute")
      Dim m2 As New Dog("Alaskan Malamute")
      Dim g1 As New Dog("Great Pyrenees")
      Dim g2 As Dog = g1
      Dim d1 As New Dog("Dalmation")
      Dim n1 As Dog = Nothing
      Dim n2 As Dog = Nothing
      
      Console.WriteLine("null = null: {0}", Object.Equals(n1, n2))
      Console.WriteLine("null Reference Equals null: {0}", Object.ReferenceEquals(n1, n2))
      Console.WriteLine()
      
      Console.WriteLine("{0} = {1}: {2}", g1, g2, Object.Equals(g1, g2))
      Console.WriteLine("{0} Reference Equals {1}: {2}", g1, g2, Object.ReferenceEquals(g1, g2))
      Console.WriteLine()
      
      Console.WriteLine("{0} = {1}: {2}", m1, m2, Object.Equals(m1, m2))
      Console.WriteLine("{0} Reference Equals {1}: {2}", m1, m2, Object.ReferenceEquals(m1, m2))
      Console.WriteLine()
      
      Console.WriteLine("{0} = {1}: {2}", m1, d1, Object.Equals(m1, d1))  
      Console.WriteLine("{0} Reference Equals {1}: {2}", m1, d1, Object.ReferenceEquals(m1, d1))  
   End Sub
End Module

Public Class Dog
   ' Public field.
   Public Breed As String
   
   ' Class constructor.
   Public Sub New(dogBreed As String)
      Me.Breed = dogBreed
   End Sub

   Public Overrides Function Equals(obj As Object) As Boolean
      If obj Is Nothing OrElse Not typeof obj Is Dog Then
         Return False
      Else
         Return Me.Breed = CType(obj, Dog).Breed
      End If   
   End Function
   
   Public Overrides Function GetHashCode() As Integer
      Return Me.Breed.GetHashCode()
   End Function
   
   Public Overrides Function ToString() As String
      Return Me.Breed
   End Function
End Class
' The example displays the following output:
'       null = null: True
'       null Reference Equals null: True
'       
'       Great Pyrenees = Great Pyrenees: True
'       Great Pyrenees Reference Equals Great Pyrenees: True
'       
'       Alaskan Malamute = Alaskan Malamute: True
'       Alaskan Malamute Reference Equals Alaskan Malamute: False
'       
'       Alaskan Malamute = Dalmation: False
'       Alaskan Malamute Reference Equals Dalmation: False

Comentarios

El método estático Equals(Object, Object) indica si dos objetos, objA y objB, son iguales. También permite probar objetos cuyo valor es NULL para determinar si son iguales. Compara objA y objB para la igualdad de la siguiente manera:

• Determina si los dos objetos representan la misma referencia de objeto. Si lo hacen, el método devuelve true. Esta prueba equivale a llamar al ReferenceEquals método . Además, si y objAobjB son NULL, el método devuelve true.

• Determina si objA o objB es null. Si es así, devuelve false.

• Si los dos objetos no representan la misma referencia de objeto y ninguno es NULL, llama a objA.Equals(objB) y devuelve el resultado. Esto significa que si objA invalida el Object.Equals(Object) método , se llama a esta invalidación.

Consulte también

• Equals(Object)
• ReferenceEquals(Object, Object)