Example 1: Program to Check Prime Number using a for loop
public class Main { public static void main(String[] args) { int num = 29; boolean flag = false; for (int i = 2; i <= num / 2; ++i) { // condition for nonprime number if (num % i == 0) { flag = true; break; } } if (!flag) System.out.println(num + " is a prime number."); else System.out.println(num + " is not a prime number."); } }
Output
29 is a prime number.
Example 2: Program to Check Prime Number using a while loop
public class Main { public static void main(String[] args) { int num = 33, i = 2; boolean flag = false; while (i <= num / 2) { // condition for nonprime number if (num % i == 0) { flag = true; break; } ++i; } if (!flag) System.out.println(num + " is a prime number."); else System.out.println(num + " is not a prime number."); } }
Output
33 is not a prime number.
