35. Prime Number Validation - prabhatrocks07/Core-Java-Programming GitHub Wiki

public class PrimeTest {

public static void main(String[] args) {
	System.out.println("--Enter any Number--");
	Scanner sc = new Scanner(System.in);
	int n = sc.nextInt();
	sc.close();
	
	if(isPrime(n)) {
		System.out.println(n + " is a prime number.");
	} else {
		System.out.println(n + " is not a prime number.");
	}
}

private static boolean isPrime(int n) {
	if(n == 1) {
		return false;
	}
	
	for (int i = 2; i <= Math.sqrt(n); i++) {
		if(n % i == 0) {
			return false;
		}
	}
	return true;
}
}