how to find the greatest common factor on java code example

Example 1: Java program find GCD and LCM of two numbers using euclid’s algorithm

import java.util.Scanner;
public class GCDLCMEuclid 
{
   // gcd java
   void findGCD(long num1, long num2)
   {
      while(num2 > 0)
      {
         long temp = num2;
         num2 = num1 % num2;
         num1 = temp;
      }
      System.out.println("GCD is : " + num1);
   }
   // lcm java
   void findLCM(long num1, long num2)
   {
      long a = num1;
      long b = num2;
      while(num2 > 0)
      {
         long temp = num2;
         num2 = num1 % num2;
         num1 = temp;
      }
      long gcd = num1;
      long lcm = (a * (b / gcd));
      System.out.println("LCM is : " + lcm);
   }
   public static void main(String[] args)
   {
      GCDLCMEuclid obj = new GCDLCMEuclid();
      System.out.println("Please enter any two numbers to find GCD : ");
      Scanner sc = new Scanner(System.in);
      long a = sc.nextLong();
      long b = sc.nextLong();
      obj.findGCD(a, b);
      System.out.println("Please enter any two numbers to find LCM : ");
      long c = sc.nextLong();
      long d = sc.nextLong();
      obj.findLCM(c, d);
      sc.close();
   }
}

Example 2: gcd in java

public class GCD {

    public static void main(String[] args) {

        int n1 = 81, n2 = 153, gcd = 1;

        for(int i = 1; i <= n1 && i <= n2; ++i)
        {
            // Checks if i is factor of both integers
            if(n1 % i==0 && n2 % i==0)
                gcd = i;
        }

        System.out.printf("G.C.D of %d and %d is %d", n1, n2, gcd);
    }
}

Example 3: greatest common divisor java

import java.util.Scanner;
public class GCDExample3 {

    public static void main(String[] args) {

        int num1, num2;
        
        //Reading the input numbers
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter first number:");
        num1 = (int)scanner.nextInt();
        
        System.out.print("Enter second number:");
        num2 = (int)scanner.nextInt();
        
        //closing the scanner to avoid memory leaks
        scanner.close();
        while (num1 != num2) {
        	if(num1 > num2)
                num1 = num1 - num2;
            else
                num2 = num2 - num1;
        }

        //displaying the result
        System.out.printf("GCD of given numbers is: %d", num2);
    }