质数的判断

import java.util.Scanner;

public class FunctionDemo3 {
    public static void main(String[] args) {
        System.out.print("请输入一个整数: ");
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
        judgePrimeNum(num);
    }
    public static void judgePrimeNum(int n) {
        if(n == 1 || n == 0) {
            System.out.println(n + " 不是质数！");
        }
        else if (n == 2) {
            System.out.println(n + " 是质数！");
        }
        else {
            for (int i = 2; i < n; i++) {
                if(n % 2 == 0) {
                    System.out.println(n + " 不是质数！");
                    return;
                }

            }
            System.out.println(n + " 是质数！");
        }
    }
}