第六次作业

1:完善menu注册功能,抽奖,看小故事等功能

package method;

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");
        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: registerNatives(); 
            break; 
        case 3: choujiang();
            break;
        case 4: look(); 
            break;
        case 5: esc();
            break;
        default:
            System.out.println("输入有误请重新输入:");
            mainMenu();
        }

}
    public static void registerNatives() { 
        System.out.println("请输入用户名:"); 
        Scanner input = new Scanner(System.in); 
        input.nextLine(); 
        System.out.println("请输入密码:"); 
        input.nextLine();
         System.out.println("注册完成"); 
        returnMain(); 
        } 
    public static void choujiang() { 
        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 x = input.nextInt(); 
        int y = sj.nextInt(); 
        int z = (x % 100) / 10; 
        if (z == y) { 
            System.out.println("恭喜您成为幸运会员"); 
            } else { 
                System.out.println("很抱歉您不是幸运会员"); 
                } 
        returnMain(); 
        } 
    private static void login() {
        // TODO Auto-generated method astub
        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("请输入您想要看的故事名称"); 
            Scanner input = new Scanner(System.in); 
            input.next(); 
            System.out.println("感谢您的观看"); 
            returnMain(); 
            } 
        public static void esc() { 
            System.out.println("谢谢您的使用"); 
        }
    }

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 computer;

import java.util.Scanner;

public class wm {
    
     public static double jc(int a){
            int x=1;
            for(int i=1;i<=a;i++){
                x*=i;
            }
            return x;
        }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input= new Scanner(System.in);
        System.out.println("请输入数字：");
        int i=input.nextInt();
        System.out.println("阶乘等于："+jc(i));
    }

}

3.编写一个方法，判断该年份是平年还是闰年。

package computer;

public class wm {
    public static void main(String[] args) {
          near(1991);
        } 
         public static void near(int y){
       if (y % 4 == 0 && y % 100 != 0 || y % 400 == 0) {
               System.out.println(y + "年是闰年");
               } else {
                         System.out.println(y + "年不是闰年");
               }
          }

}