program to print series of prime numbers using java

Question

This code is to print the series of prime number up to given limit but when I am trying to execute this,it goes into infinite loop.

import java.io.*;
class a
{
          


        

Answer 1

You can take a look at this code.

import java.io.*;
public class Main {

     public static void main(String[] args) throws IOException {

        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        //How many prime numbers you want to print?
        String s = bf.readLine();
        int n = Integer.parseInt(s);
        int count = 0;
        boolean loop = true;
        for(int i =2 ; loop ; i++){

            if(isPrime(i))
                {
                System.out.println(i + " ");
                count++;
                }
            if(count == n)
                loop = false;
        }
    }

The following isPrime() method checks whether a number is prime or not. If the number is prime, it returns true, otherwise false.

    public static boolean isPrime(int num) {
        boolean prime = true;
        for(int i=2 ; i<= Math.sqrt(num);){
            if(num % i ==  0)
                {
                    prime = false;
                    break;
                }
            if(i >= 3)
            /* when i>=3 we do not need to check for every number. 
              For avoiding even numbers i is incremented by 2. 
              It reduces the number of looping */ 
                i+=2;
            else
                i++;
        }

        return prime;

    }
}