how to find prime numbers between two numbers in java code example

Example 1: Java program to find LCM of two numbers

public class LCMOfTwoNumbers
{
   public static void main(String[] args)
   { 
      int num1 = 85, num2 = 175, lcm;
      lcm = (num1 > num2) ? num1 : num2;
      while(true)
      {
         if(lcm % num1 == 0 && lcm % num2 == 0)
         {
            System.out.println("LCM of " + num1 + " and " + num2 + " is " + lcm + ".");
            break;
         }
         ++lcm;
      }
   }
}

Example 2: Java program to find LCM of two numbers

calculate lcm two numbers in java we can use GCD
public class LCMUsingGCD 
{
   public static void main(String[] args) 
   {
      int num1 = 15, num2 = 25, gcd = 1;
      for(int a = 1; a <= num1 && a <= num2; ++a)
      {
         if(num1 % a == 0 && num2 % a == 0)
         {
            gcd = a;
         }
      }
      int lcm = (num1 * num2) / gcd;
      System.out.println("LCM of " + num1 + " and " + num2 + " is " + lcm + ".");
   }
}

Example 3: making list of prime numbers java

Now let’s see print first 10 prime numbers in java.

public class FirstTenPrimeNumbers
{
   public static void main(String[] args) 
   {
      int count = 0, number = 0, a = 1, b = 1;  
      while(number < 10)  
      {  
         b = 1;  
         count = 0;  
         while(b <= a)  
         {  
            if(a%b == 0)  
                count++;  
            b++;
         }  
         if(count == 2)  
         {  
            System.out.printf("%d ", a);  
            number++;  
         }  
         a++;  
      }
   }
}

Example 4: primenumbers java

It will display the prime numbers between 1 and 100.

class PrimeNumbers
{
   public static void main (String[] args)
   {		
       int i =0;
       int num =0;
       //Empty String
       String  primeNumbers = "";

       for (i = 1; i <= 100; i++)         
       { 		  	  
          int counter=0; 	  
          for(num =i; num>=1; num--)
	  {
             if(i%num==0)
	     {
 		counter = counter + 1;
	     }
	  }
	  if (counter ==2)
	  {
	     //Appended the Prime number to the String
	     primeNumbers = primeNumbers + i + " ";
	  }	
       }	
       System.out.println("Prime numbers from 1 to 100 are :");
       System.out.println(primeNumbers);
   }
}