java prime numbers

1public class Main {
2  public static void main(String[] args) {
3    for (int i = 2; i < 1_000_000; ++i) {
4      boolean isPrime = true;
5      int sqrt = (int)Math.ceil(Math.sqrt(i));
6      for (int divisor = 2; divisor <= sqrt; ++divisor) {
7        if (i % divisor == 0) {
8          isPrime = false;
9          break;
10        }
11      }
12      if (isPrime) {
13        System.out.println(i);
14      }
15    }
16  }
17}

1public class Prime {
2    public static void main(String[] args) {
3
4        int num = 29;
5        boolean flag = false;
6        for(int i = 2; i <= num/2; ++i){
7            if(num % i == 0){
8                flag = true;
9                break;
10            }
11        }
12
13        if (!flag)
14            System.out.println(num + " is a prime number.");
15        else
16            System.out.println(num + " is not a prime number.");
17}}

1public class Prime {
2    public static void main(String[] args) {
3
4        int num = 29;
5        boolean flag = false;
6        for(int i = 2; i <= num/2; ++i){
7            if(num % i == 0){
8                flag = true;
9                break;
10            }
11        }
12
13        if (!flag)
14            System.out.println(num + " is a prime number.");
15        else
16            System.out.println(num + " is not a prime number.");
17}}
18Source:www.progra
19

1public class Prime {
2
3    public static void main(String[] args) {
4
5        int num = 29;
6        boolean flag = false;
7        for(int i = 2; i <= num/2; ++i)
8        {
9            // condition for nonprime number
10            if(num % i == 0)
11            {
12                flag = true;
13                break;
14            }
15        }
16
17        if (!flag)
18            System.out.println(num + " is a prime number.");
19        else
20            System.out.println(num + " is not a prime number.");
21    }
22}

1public class PrimeNumberInJava
2{
3   public static void main(String[] args)
4   {
5      int a, b = 0, flag = 0;
6      int number = 17;
7      b = number / 2;
8      if(number == 0 || number == 1)
9      {
10         System.out.println(number + " is not prime number");
11      }
12      else
13      {
14         for(a = 2; a <= b; a++)
15         {
16            if(number % a == 0)
17            {
18               System.out.println(number + " is not prime number.");
19               flag = 1;
20               break;
21            }
22         }
23         if(flag == 0)
24         {
25            System.out.println(number + " is prime number.");
26         }
27      }
28   }
29}

1It will display the prime numbers between 1 and 100.
2
3class PrimeNumbers
4{
5   public static void main (String[] args)
6   {		
7       int i =0;
8       int num =0;
9       //Empty String
10       String  primeNumbers = "";
11
12       for (i = 1; i <= 100; i++)         
13       { 		  	  
14          int counter=0; 	  
15          for(num =i; num>=1; num--)
16	  {
17             if(i%num==0)
18	     {
19 		counter = counter + 1;
20	     }
21	  }
22	  if (counter ==2)
23	  {
24	     //Appended the Prime number to the String
25	     primeNumbers = primeNumbers + i + " ";
26	  }	
27       }	
28       System.out.println("Prime numbers from 1 to 100 are :");
29       System.out.println(primeNumbers);
30   }
31}