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Enum.Equals(Object) Method

Definition

Returns a value indicating whether this instance is equal to a specified object.

public override bool Equals (object obj);
public override bool Equals (object? obj);

Parameters

obj
Object

An object to compare with this instance, or null.

Returns

true if obj is an enumeration value of the same type and with the same underlying value as this instance; otherwise, false.

Examples

The following example illustrates the use of the Equals method.

using System;

public class EqualsTest {
    enum Colors { Red, Green, Blue, Yellow };
    enum Mammals { Cat, Dog, Horse, Dolphin };

    public static void Main() {
        Mammals myPet = Mammals.Cat;
        Colors myColor = Colors.Red;
        Mammals yourPet = Mammals.Dog;
        Colors yourColor = Colors.Red;

        Console.WriteLine("My favorite animal is a {0}", myPet);
        Console.WriteLine("Your favorite animal is a {0}", yourPet);
        Console.WriteLine("Do we like the same animal? {0}", myPet.Equals(yourPet) ? "Yes" : "No");

        Console.WriteLine();
        Console.WriteLine("My favorite color is {0}", myColor);
        Console.WriteLine("Your favorite color is {0}", yourColor);
        Console.WriteLine("Do we like the same color? {0}", myColor.Equals(yourColor) ? "Yes" : "No");

        Console.WriteLine();
        Console.WriteLine("The value of my color ({0}) is {1}", myColor, Enum.Format(typeof(Colors), myColor, "d"));
        Console.WriteLine("The value of my pet (a {0}) is {1}", myPet, Enum.Format(typeof(Mammals), myPet, "d"));
        Console.WriteLine("Even though they have the same value, are they equal? {0}",
                    myColor.Equals(myPet) ? "Yes" : "No");
    }
}
// The example displays the following output:
//    My favorite animal is a Cat
//    Your favorite animal is a Dog
//    Do we like the same animal? No
//
//    My favorite color is Red
//    Your favorite color is Red
//    Do we like the same color? Yes
//
//    The value of my color (Red) is 0
//    The value of my pet (a Cat) is 0
//    Even though they have the same value, are they equal? No

The following example defines two enumeration types, SledDog and WorkDog. The SledDog enumeration has two members, SledDog.AlaskanMalamute and SledDog.Malamute, that have the same underlying value. The call to the Equals method indicates that these values are equal because their underlying values are the same. The SledDog.Malamute and WorkDog.Newfoundland members have the same underlying value, although they represent different enumeration types. A call to the Equals method indicates that these values are not equal.

using System;

public enum SledDog { Unknown=0, AlaskanMalamute=1, Malamute=1,
                      Husky=2, SiberianHusky=2 };

public enum WorkDog { Unknown=0, Newfoundland=1, GreatPyrennes=2 };

public class Example
{
   public static void Main()
   {
      SledDog dog1 = SledDog.Malamute;
      SledDog dog2 = SledDog.AlaskanMalamute;
      WorkDog dog3 = WorkDog.Newfoundland;

      Console.WriteLine("{0:F} ({0:D}) = {1:F} ({1:D}): {2}",
                        dog1, dog2, dog1.Equals(dog2));
      Console.WriteLine("{0:F} ({0:D}) = {1:F} ({1:D}): {2}",
                        dog1, dog3, dog1.Equals(dog3));
   }
}
// The example displays the following output:
//       Malamute (1) = Malamute (1): True
//       Malamute (1) = Newfoundland (1): False

Remarks

The Enum.Equals(Object) method overrides ValueType.Equals(Object) to define how enumeration members are evaluated for equality.

Applies to

Prodotto Versioni
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1
UWP 10.0

See also