第十一次Java作业

1.完善menu注册功能,抽奖,看小故事等功能

package snippet;
import java.util.*;
public class Snippet {
    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:
        choujiang();
        break;
        case 4:
        story();
        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();
        }

        private static void choujiang() {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入四位会员卡号：");
        int x = input.nextInt();
        Random r = new Random();
        int j = r.nextInt(10);
        if (x / 100 * 10 == j) {
        System.out.println("恭喜 你中奖了!");
        } else {
        System.out.println("感谢您的参与");
        }
        returnMain();
        }

        public static void story() {
        Scanner input = new Scanner(System.in);
        System.out.println("请选择你想看的故事：");
        
        
        }

        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");
        }
        }
        }

 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

package snippet;
import java.util.*;
public class Snippet {
    public static int jc(int n) {
        int cj=1;
        for (int i = 1; i <= n; i++) {
        cj*=i;
        }
        return cj;
        }
        public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        System.out.println("请输入要求阶乘的数字：");
        int i=sc.nextInt();
        System.out.println("该数字的阶乘为：" + jc(i));
        }
        }

 3.

.编写一个方法，判断该年份是平年还是闰年。

package snippet;
import java.util.*;
public class year {
    public static void year(int n) {
    if (n % 4 == 0 && n % 100 != 0 || n % 400 == 0) {
    System.out.println("该年是闰年");
    } else {
    System.out.println("该年是平年");
    }
    }

    public static void main(String[] args) {
    year a = new year();
    Scanner sc = new Scanner(System.in);
    System.out.println("请输入年份：");
    int i=sc.nextInt();
    year(i);
    }
    }