Int32.CompareTo Method in C# with Examples

Int32.CompareTo Method is used to compare the current instance to a specified object or Int32 and returns a sign of their relative values. There are 2 methods in the overload list of this method as follows:

• CompareTo(Int32) Method
• CompareTo(Object) Method

Int32.CompareTo(Int32) Method

This method is used to compare the current instance to a specified 32-bit signed integer and returns a sign of their relative values.

Syntax:

public int CompareTo (int value);

Here, it takes integer to compare.

Return Value: It returns a 32-bit signed number indicating the relative values of current instance and value parameter as follows:

• Less than Zero: if Current Instance < value
• Zero: if Current Instance = value
• Greater than Zero: if Current Instance > value

Below programs illustrate the use of the above-discussed method:

Example 1:

// C# program to demonstrate the
// Int32.CompareTo(Int32) Method
using System;

class GFG {

    // Main Method
    public static void Main()
    {

        // Declaring and initializing value1
        int value1 = 10;

        // Declaring and initializing value2
        int value2 = 20;

        // using CompareTo() method
        int status = value1.CompareTo(value2);

        // checking the status
        if (status > 0)
            Console.WriteLine("{0} is greater than {1}",
                                        value1, value2);
        else if (status < 0)
            Console.WriteLine("{0} is less than {1}",
                                     value1, value2);
        else
            Console.WriteLine("{0} is equal to {1}",
                                    value1, value2);
    }
}

Output:

10 is less than 20

Example 2:

// C# program to demonstrate the
// Int32.CompareTo(Int32) Method
using System;

class GFG {

    // Main Method
    public static void Main()
    {
        // calling get() method
        get(5, 7);
        get(3025, 3025);
        get(10, 20);
        get(7, -12);
    }

    // defining get() method
    public static void get(int value1,
                           int value2)
    {

        // using the method
        int status = value1.CompareTo(value2);

        // checking the status
        if (status > 0)
            Console.WriteLine("{0} is greater than {1}",
                                       value1, value2);
        else if (status < 0)
            Console.WriteLine("{0} is less than {1}",
                                     value1, value2);
        else
            Console.WriteLine("{0} is equal to {1}",
                                    value1, value2);
    }
}

Output:

5 is less than 7
3025 is equal to 3025
10 is less than 20
7 is greater than -12

Int32.CompareTo(Object) Method

This method is used to compare the current instance to a specified object and returns a sign of their relative values.

Syntax:

public int CompareTo (object value);

Here, it takes an object to compare, or null.

Return Value: It returns a 32-bit signed number indicating the relative values of current instance and value parameter as follows:

• Less than Zero: if Current Instance < value
• Zero: if Current Instance = value
• Greater than Zero: if Current Instance > value or value is null.

Exception: It throws ArgumentException if value is not an Int32.

Below programs illustrate the use of the above-discussed method:

Example 1:

// C# program to demonstrate the
// Int32.CompareTo(Object) Method
using System;

class GFG {

    // Main Method
    public static void Main()
    {
        try {

            // Declaring and initializing value1
            int value1 = 10;

            // Declaring and initializing value2
            object value2 = 562587;

            // using CompareTo() method
            int status = value1.CompareTo(value2);

            // checking the status
            if (status > 0)
                Console.WriteLine("{0} is greater than {1}",
                                           value1, value2);

            else if (status < 0)
                Console.WriteLine("{0} is less than {1}",
                                         value1, value2);
            else
                Console.WriteLine("{0} is equal to {1}",
                                        value1, value2);
        }

        catch (ArgumentException e)
        {
            Console.WriteLine("value2 must be Int32");
            Console.Write("Exception Thrown: ");
            Console.Write("{0}", e.GetType(), e.Message);
        }
    }
}

Output:

10 is less than 562587

Example 2: For ArgumentException

// C# program to demonstrate the
// Int32.CompareTo(object) Method
using System;
using System.Globalization;

class GFG {

    // Main Method
    public static void Main()
    {
        try {

            // Declaring and initializing value1
            int value1 = 10;

            // Declaring and initializing value2
            object value2 = 9856745963;

            // using CompareTo() method
            int status = value1.CompareTo(value2);

            // checking the status
            if (status > 0)
                Console.WriteLine("{0} is greater than {1}",
                                            value1, value2);

            else if (status < 0)
                Console.WriteLine("{0} is less than {1}",
                                         value1, value2);
            else
                Console.WriteLine("{0} is equal to {1}",
                                        value1, value2);
        }

        catch (ArgumentException e)
        {
            Console.WriteLine("value2 must be Int32");
            Console.Write("Exception Thrown: ");
            Console.Write("{0}", e.GetType(), e.Message);
        }
    }
}

Output:

value2 must be Int32
Exception Thrown: System.ArgumentException

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.int32.compareto?view=netframework-4.7.2