How To Compare Enum Values In C#

The current instance can be compared to a given object using the Enum.CompareTo(Object) method, which provides a relative value indication.

Syntax:

It has the following syntax:

public int CompareTo(object target);

• ✅ public: It indicates the method's level of access. It indicates that the method may be accessed from outside the class.
• ✅ int: It denotes that an integer value is returned by the method.
• ✅ CompareTo: The name of the method.
• ✅ (object target): It indicates the method's parameter. It takes an object (target) as input to compare an object with the current object.

Return Value

• ✅ Negative integer: The current object is less than the target object.
• ✅ Zero: The current object is equal to the target object.
• ✅ Positive integer: The current object is greater than the target object.

Exceptions

• ✅ ArgumentException: It will occur when the type of the target and the current instance differ.
• ✅ InvalidOperationException: If the instance is not of type SByte, Int16, Int32, Int64, Byte, UInt16, UInt32, or UInt64, an invalid operation exception will occur.
• ✅ NullReferenceException: If the instance is null, NullReferenceException is raised.

Example-1:

Let us take an example to demonstrate how to compare enum values in C#.

using System; 
public class Demo 
{ 
	enum Days
	{ 
		Monday, Wednesday, Friday 
	}; 
	public static void Main(String[] args) 
	{ 
		Days day_1 = Days.Monday; 
	    Days day_2 = Days.Wednesday; 
		Days day_3 = Days.Monday; 
		Days day_4 = Days.Friday; 
		Console.Write("Comparing {0} with {1}: ", day_1, day_2); 
		Console.WriteLine(day_1.CompareTo(day_2)); 
		Console.Write("Comparing {0} with {1}: ", day_1, day_3); 
		Console.WriteLine(day_1.CompareTo(day_3)); 
		Console.Write("Comparing {0} with {1}: ", day_4, day_2); 
		Console.WriteLine(day_4.CompareTo(day_2)); 
	} 
}

Output:

Comparing Monday with Wednesday: -1
Comparing Monday with Monday: 0
Comparing Friday with Wednesday: 1

Explanation:

• ✅ In this example, the Days enum's enum values may be compared using the CompareTo method, which is shown in this C# code.

Inside the main method:

• ✅ Specific enum values corresponding to Monday, Wednesday, and Friday are defined and initialized for the enum values day1, day2, day3, and day4.
• ✅ Day 1, Day 2, and Day 4 are compared with other enum values (day 2, Day 3, and Day 2) using the CompareTo method.
• ✅ The relative order of the enum values is displayed in the comparison results, which are printed to the console using WriteLine .
• ✅ For example, the enum definition puts Monday (day 1) before Wednesday (day 2). Therefore, the initial comparison (day 1 vs. day 2) has a negative number (-1).
• ✅ As day1 and day3 represent Monday, the second comparison (day1 vs. day3) returns a zero (0) result.
• ✅ As Friday (day 4) appears after Wednesday (day 2) in the enum specification, the third comparison (day4 vs. day2) returns a positive result (1).

Example-2:

Let us take another example to demonstrate how to compare enum values in C#.

using System;
//Defining an enum
public enum DayofWeek
{
    Monday,
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday,
    Sunday
}
class Demo
{
    static void Main(string[] args)
    {
        // Example 1: Using Equality Comparison
        DayofWeek today = DayofWeek.Friday;
        DayofWeek tomorrow = DayofWeek.Wednesday;
        if (today == tomorrow)
        {
            Console.WriteLine("Today and Tomorrow both are the same day.");
        }
        else
        {
            Console.WriteLine("Today and Tomorrow are both different days.");
        }
        // Example 2: Using Comparison Methods
        DayofWeek day_1 = DayofWeek.Wednesday;
        DayofWeek day_2 = DayofWeek.Saturday;
        if (Enum.Equals(day_1, day_2))
        {
            Console.WriteLine("Day1 and Day2 both are equal.");
        }
        else
        {
            Console.WriteLine("Day1 and Day2 are both not equal.");
        }
        // Example 3: Using Switch Statement
        DayofWeek chosenDay = DayofWeek.Friday;
        switch (chosenDay)
        {
            case DayofWeek.Saturday:
            case DayofWeek.Sunday:
                Console.WriteLine("It's a wonderful weekend!");
                break;
            default:
                Console.WriteLine("It's a boring weekday.");
                break;
        }
    }
}

Output:

Today and Tomorrow are both different days.
Day 1 and Day 2 are both not equal.
It's a boring weekday.

Explanation:

This C# code demonstrates many methods for comparing enum values:

• ✅ Equality Comparison: The '==' operator compares two enum values (Today and Tomorrow). It prints the result based on whether the results are the same or different.
• ✅ Comparison Methods: The Equals method compares two enum values (day1 and day2). It determines whether or not they are equal and prints the result accordingly.
• ✅ Switch Statement: A switch statement is used to determine the value of the chosenDay enum variable. It prints "It's a wonderful weekend!" if Saturday or Sunday is selected. If not, "It's a boring weekday" is printed.

This code acts as an overall example of how to compare enum values in C# and shows how to handle enum values depending on different situations by using equality comparison, comparison methods, and switch statements.