Java练习题-质数判断

判断一个数是不是质数

package com.itheima.test08;

import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("请输入一个数:");
            int num = sc.nextInt();
            boolean flag = true;
            for (int i = 2; i < num; i++) {
                if (num==1||num==2){
                    break;
                }
                if (num%i==0){
                    flag = false;
                    break;
                }
            }


            if (flag==true){
                System.out.println(num+"质数");
            }else {
                System.out.println(num+"不是质数");

            }
        }
    }
}