Example: Java Program to Print Prime Numbers from 1 to N using For loop

// Java Program to Print Prime Numbers from 1 to N using For loop
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
    	Scanner in = new Scanner(System.in);

        int x, i, j, f;

        System.out.println ("Please enter the range for print the prime numbers::\n");
        x = in.nextInt();

        System.out.println ("\nThe prime numbers from 1 to " + x + " are::\n\n");

        for (i = 1; i <= x; i++) {
            
            // They are niether prime nor composite if as skip 0 and 1
            if (i == 1 || i == 0) {
                continue;
            }
            
            f = 1;
     
            for (j = 2; j <= i / 2; ++j) {
                if (i % j == 0) {
                    f = 0;
                    break;
                }
            }

            // f = 1 means i is prime and f = 0 means i is not prime
            if (f == 1) {
                System.out.print (" " + i);
            }
        }
        System.out.println ("\n");
    }
}