第八周作业

完善menu功能.

package zy;
import java.util.Random;
import java.util.Scanner;

public class PersonCreate {

    public static void main(String[] args) {
         mainMenu();
}
    public static void mainMenu() {
        Scanner input = new Scanner(System.in);
        System.out.println("1.登录");
        System.out.println("2.注册");
        System.out.println("3.幸运抽奖.");
        System.out.println("4.看小故事,");
        System.out.println("5.退出系统");
        System.out.println("请选择");
        int i = input.nextInt();
        switch (i) {
        case 1:
            login();
            break;
        case 2:
            zhuce();
            break;
        case 3:
            xingyuncj();
            break;
        case 4:
            xiaogushi();
            break;
        case 5:
            tuichu();
            break;
            
        }
    }

    public static void login() {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入用户名");
        String uname = input.next();
        System.out.println("输入密码");
        String upwd = input.next();
        if (uname.equals("zs") && upwd.equals("123")) {
            System.out.println("登录成功");
        } else {
            System.out.println("登录失败");
        }
        returnMain();
    
    }
    public static void zhuce() {
        Scanner input = new Scanner(System.in);
        System.out.println("用户名");
        String uname = input.next();
        System.out.println("密码");
        String upwd = input.next();
        if(uname.equals(null) || upwd.equals(null) ) {
            System.out.println("注册失败");
        }else {
            System.out.println("注册成功");
        }
        returnMain();
    }
    public static void xingyuncj() {
        System.out.println("1.作弊模式");
        System.out.println("2.正常模式");
        Scanner input = new Scanner(System.in);
        int x=input.nextInt();
        switch(x) {
        case 1:
            zuobi();
            break;
        case 2:
            zhengchang();
            break;
        }
    }
    public static void zuobi() {
        Scanner input = new Scanner(System.in);
        System.out.println("作弊模式：");
        Random r=new Random();
        int sjs=r.nextInt(10);
        System.out.println(sjs);
        System.out.println("请输入四位会员数");
        int num=input.nextInt();
        if(num/100%10==sjs) {
            System.out.println("恭喜你，是幸运会员");
        }else {
            System.out.println("祝你下次好运");
        }
        returnMain();
    }
    public static void zhengchang() {
        Scanner input = new Scanner(System.in);
        System.out.println("正常模式");
        Random r=new Random();
        int sjs=r.nextInt(10);
        System.out.println("请输入四位会员数");
        int num=input.nextInt();
        if(num/100%10==sjs) {
            System.out.println("恭喜你，是幸运会员");
        }else {
            System.out.println("祝你下次好运");
        }
        returnMain();
    }
    public static void xiaogushi() {
        System.out.println("把大象装进冰箱分成几个步骤");
        System.out.println("1.冰箱门打开");
        System.out.println("2.大象放进去");
        System.out.println("3.冰箱门关上");
        returnMain();
    }
    public static void tuichu() {
        System.out.println("是否退出系统Y/N");
        Scanner input = new Scanner(System.in);
        String a = input.next();
        if(a.equalsIgnoreCase("y")) {
            System.out.println("退出系统成功");
        }else {
            returnMain();
        }
    } 
    
    public static void returnMain(){
        System.out.println("是否返回主菜单?Y/N");
        Scanner input = new Scanner(System.in);
        if (input.next().equalsIgnoreCase("Y")) {
            mainMenu();
        }else{
            System.out.println("谢谢使用");
        }

    }
}

编写一个方法，求整数n的阶乘，例如5的阶乘是1*2*3*4*5.

package zy;

public class jiecheng {

    public static void main(String[] args) {
          jiecheng p=new jiecheng();
            p.method(5);
        }
        public void method(int a) {
            int b=1;
            for(int i=1;i<=a;i++) {
                b*=i;
            }
            a=b;
            System.out.println(a);
        }
    
}

编写一个方法，判断该年份是平年还是闰年.

package zy;

public class runnian {

    public static void main(String[] args) {
        runnian p = new runnian();
            p.method(2000);
        }
        public void method(int year) {
            int a;
            a=year;
            if(a%4==0 && a%100!=0 || a%400==0) {
                System.out.println(a+"是闰年");
            }else {
                System.out.println(a+"不是闰年");
            }

    }

}