C# program to find the HCF of two given numbers

Here, we are going to learn how to find the HCF of two given numbers in C#? By Nidhi Last updated : April 15, 2023

Finding HCF of Two Numbers

Here we will enter two integer numbers from the keyboard and then find the highest common factor of two numbers.

Example

Numbers:		9, 15
Factors of 9 are:  	1, 3, 9
Factors of 15 are:	 1, 3, 5, 15 	
Then the Highest Common Factor will be 3.

C# code for finding HCF of two numbers

The source code to find the HCF of two numbers is given below. The given program is compiled and executed successfully on Microsoft Visual Studio.

//C# program to find the HCF of two given numbers.

using System;

class HcfClass
{
    static int GetHcf(int number1, int number2)
    {
        int iLoop = 1;
        int hcf = 0;
        
        while (iLoop <= number1 || iLoop <= number2)
        {
            if (number1 % iLoop == 0 && number2 % iLoop == 0)
                hcf = iLoop;
            iLoop++;
        }

        return hcf;
    }
    static void Main(string[] args)
    {
        int number1=0;
        int number2=0;
            
        int hcf = 0;

        Console.Write("Enter the First Number : ");
        number1 = int.Parse(Console.ReadLine());

        Console.Write("Enter the Second Number : ");
        number2 = int.Parse(Console.ReadLine());

        hcf = GetHcf(number1, number2);

        Console.Write("\nHighest Common Factor is : ");
        Console.WriteLine(hcf);
    }
}

Output

Enter the First Number : 15
Enter the Second Number : 9

Highest Common Factor is : 3
Press any key to continue . . .

Explanation

Here, we created a class HcfClass that contains two methods GetHcf() and Main(). In the GetHcf(), we find the highest common factor of two numbers.

while (iLoop <= number1 || iLoop <= number2)
{
    if (number1 % iLoop == 0 && number2 % iLoop == 0)
        hcf = iLoop;
    iLoop++;
}

In the above code, we checked the common factor of both numbers, the loop executed till the value of counter variable iLoop is less than and equal to anyone of the given number and update the value of the common factor. That's why we loop ends then we have the highest common factor. The GetHcf() method returns the HCF to the calling method.

In the Main() method, we read the values of two integer numbers and then calculated the HCF. Then the HCF is printed on the console screen.