1. Introduction

In this tutorial, we’ll explore a Java program designed to calculate the Greatest Common Divisor (GCD) of two numbers. The GCD of two integers is the largest positive integer that divides both numbers without leaving a remainder. For example, the GCD of 8 and 12 is 4.

2. Program Steps

1. Define a class named GCD_Calculator.

2. Define the main method inside this class.

3. Inside the main method, initialize two integer variables num1 and num2 with the numbers for which you want to find the GCD.

4. Call the findGCD method, passing num1 and num2 as parameters.

5. Print the calculated GCD.

3. Code Program

public class GCD_Calculator { // 1. Define the class

    // Method to find GCD of two numbers using Euclidean algorithm
    static int findGCD(int a, int b) {
        if (b == 0)
            return a;
        else
            return findGCD(b, a % b);
    }

    public static void main(String[] args) { // 2. Define the main method

        int num1 = 56, num2 = 98; // 3. Initialize num1 and num2

        // 4. Call the findGCD method and store the result in variable 'gcd'
        int gcd = findGCD(num1, num2);

        // 5. Print the result
        System.out.println("GCD of " + num1 + " and " + num2 + " is: " + gcd);
    }
}

Output:

GCD of 56 and 98 is: 14

4. Step By Step Explanation

– Step 1: A class named GCD_Calculator is defined.

– Step 2: The main method is defined within the class, acting as the entry point for the Java program.

– Step 3: Two integer variables num1 and num2 are initialized with the values 56 and 98 respectively, for which we wish to calculate the GCD.

– Step 4: The method findGCD is called with num1 and num2 as parameters. This method employs the Euclidean algorithm to calculate the GCD. If the second number b is 0, the method returns the first number a. Otherwise, it recursively calls itself with b and the remainder of a divided by b as the parameters.

– Step 5: The program outputs the calculated GCD of 56 and 98, which is 14, to the console.