JAVA第八周作业

1.完善menu注册功能,抽奖,看小故事等功能

package one;

import java.util.Random;
import java.util.Scanner;

public class menu {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        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,输入四位会员卡号,如果百位等于系统随机数,就是星运会员.否则不是.");
        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:
            huiyuan();
            break;
        case 4:
            look();
            break;
        case 5:
            esc();
            break;
        default:
            System.out.println("输入有误重新输入");
            mainMenu();
        }
    }

    public static void zhuce() {
        System.out.println("输入用户名:");
        Scanner input = new Scanner(System.in);
        input.nextLine();
        System.out.println("输入密码:");
        input.nextLine();
        System.out.println("注册完成:");
        returnMain();
    }

    public static void huiyuan() {
        System.out.println("请输入四位会员卡号");
        Random sj = new Random(0 - 9);
        Scanner input = new Scanner(System.in);
        int w = input.nextInt();
        int shu = sj.nextInt();
        int bai = (w % 100) / 10;
        if (bai == shu) {
            System.out.println("恭喜您是幸运会员");
        } else {
            System.out.println("您不是幸运会员");
        }
        returnMain();
    }

    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 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");
        }

    }

    public static void look() {
        System.out.println("输入您想要看的故事名称");
        Scanner input = new Scanner(System.in);
        input.next();
        System.out.println("感谢观看");
        returnMain();
    }

    public static void esc() {
        System.out.println("谢谢使用");
    }

}

2.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。 [必做题]

package one;

public class jc {
    public static int jc(int x) {
        int sum = 1;
        for (int i = 1; i <= x; i++) {
            sum *= i;
        }
        return sum;
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println(jc(5));
    }

}

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package one;

public class jc {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        prn(2020);
    }

    public static void prn(int year) {
        if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
            System.out.println(year + "年是闰年");
        } else {
            System.out.println(year + "年不是闰年");
        }

    }
}