Program to find the Prime numbers till a certain range.

Explanation :
If range=100 then the output will be
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97.

Code:

import java.util.Scanner; 

public class Prime

{

   public static void main (String[] args) 

   { 

        Scanner scanner = new Scanner(System.in); 

         int i =0; int num =0; 

         //Empty String 

         String primeNumbers = ""; 

         System.out.println("Enter the value of n:"); 

         int n = scanner.nextInt(); 

         for (i = 1; i <= n; i++)

        { 

             int counter=0; 

             for(num =i; num>=1; num--)

            {

                if(i%num==0) 

               { 

                    counter = counter + 1; 

                }

            }

            if (counter ==2)

           { 

                   primeNumbers = primeNumbers + i + " "; 

            } 

        } 

      System.out.println("Prime numbers from 1 to"+ n+ " are :");

      System.out.println(primeNumbers);

    } 

}