Enum.Equals(Object) Method
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Returns a value indicating whether this instance is equal to a specified object.
public:
override bool Equals(System::Object ^ obj);
public override bool Equals (object obj);
public override bool Equals (object? obj);
override this.Equals : obj -> bool
Public Overrides Function Equals (obj As Object) As Boolean
- obj
- Object
An object to compare with this instance, or null
.
true
if obj
is an enumeration value of the same type and with the same underlying value as this instance; otherwise, false
.
The following example illustrates the use of the Equals method.
using namespace System;
public enum class Colors
{
Red, Green, Blue, Yellow
};
public enum class Mammals
{
Cat, Dog, Horse, Dolphin
};
int 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 ) ? (String^)"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 ) ? (String^)"Yes" : "No" );
Console::WriteLine();
Console::WriteLine( "The value of my color ({0}) is {1}", myColor, Enum::Format( Colors::typeid, myColor, "d" ) );
Console::WriteLine( "The value of my pet (a {0}) is {1}", myPet, Enum::Format( Mammals::typeid, myPet, "d" ) );
Console::WriteLine( "Even though they have the same value, are they equal? {0}", myColor.Equals( myPet ) ? (String^)"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
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
open System
type Colors =
| Red = 0
| Green = 1
| Blue = 2
| Yellow = 3
type Mammals =
| Cat = 0
| Dog = 1
| Horse = 2
| Dolphin = 3
let myPet = Mammals.Cat
let myColor = Colors.Red
let yourPet = Mammals.Dog
let yourColor = Colors.Red
printfn
$"""My favorite animal is a {myPet}
Your favorite animal is a {yourPet}
Do we like the same animal? {if myPet.Equals yourPet then "Yes" else "No"}
My favorite color is {myColor}
Your favorite color is {yourColor}
Do we like the same color? {if myColor.Equals yourColor then "Yes" else "No"}
The value of my color ({myColor}) is {Enum.Format(typeof<Colors>, myColor, "d")}
The value of my pet (a {myPet}) is {Enum.Format(typeof<Mammals>, myPet, "d")}
Even though they have the same value, are they equal? {if myColor.Equals myPet then "Yes" else "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
Public Class EqualsTest
Enum Colors
Red
Green
Blue
Yellow
End Enum
Enum Mammals
Cat
Dog
Horse
Dolphin
End Enum
Public Shared Sub Main()
Dim myPet As Mammals = Mammals.Cat
Dim myColor As Colors = Colors.Red
Dim yourPet As Mammals = Mammals.Dog
Dim yourColor As Colors = Colors.Red
Dim output as string
Console.WriteLine("My favorite animal is a {0}", myPet)
Console.WriteLine("Your favorite animal is a {0}", yourPet)
If myPet.Equals(yourPet) Then output = "Yes" Else output = "No"
Console.WriteLine("Do we like the same animal? {0}", output)
Console.WriteLine()
Console.WriteLine("My favorite color is {0}", myColor)
Console.WriteLine("Your favorite color is {0}", yourColor)
If myColor.Equals(yourColor) Then output = "Yes" Else output = "No"
Console.WriteLine("Do we like the same color? {0}", output)
Console.WriteLine()
Console.WriteLine("The value of my color ({0}) is {1}", myColor, [Enum].Format(GetType(Colors), myColor, "d"))
Console.WriteLine("The value of my pet (a {0}) is {1}", myPet, [Enum].Format(GetType(Mammals), myPet, "d"))
Console.WriteLine("Even though they have the same value, are they equal? {0}",
If(myColor.Equals(myPet), "Yes", "No"))
End Sub
End Class
' 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
type SledDog =
| Unknown = 0
| AlaskanMalamute = 1
| Malamute = 1
| Husky = 2
| SiberianHusky = 2
type WorkDog =
| Unknown = 0
| Newfoundland = 1
| GreatPyrennes = 2
let dog1 = SledDog.Malamute
let dog2 = SledDog.AlaskanMalamute
let dog3 = WorkDog.Newfoundland
printfn $"{dog1:F} ({dog1:D}) = {dog2:F} ({dog2:D}): {dog1.Equals dog2}"
printfn $"{dog1:F} ({dog1:D}) = {dog3:F} ({dog3:D}): {dog1.Equals dog3}"
// The example displays the following output:
// Malamute (1) = Malamute (1): True
// Malamute (1) = Newfoundland (1): False
Public Enum SledDog As Integer
Unknown=0
AlaskanMalamute=1
Malamute=1
Husky=2
SiberianHusky=2
End Enum
Public Enum WorkDog As Integer
Unknown=0
Newfoundland=1
GreatPyrennes=2
End Enum
Module Example
Public Sub Main()
Dim dog1 As SledDog = SledDog.Malamute
Dim dog2 As SledDog = SledDog.AlaskanMalamute
Dim dog3 As WorkDog = 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))
End Sub
End Module
' The example displays the following output:
' Malamute (1) = Malamute (1): True
' Malamute (1) = Newfoundland (1): False
The Enum.Equals(Object) method overrides ValueType.Equals(Object) to define how enumeration members are evaluated for equality.
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 |
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