第八周作业

1:完善menu注册功能,抽奖,看小故事等功能

package demo;
import java.util.*;
public class Menu {
	public static void main(String[] args) {
        mainMenu();
	}
	public static void mainMenu() {
        Scanner input = new Scanner(System.in);
        System.out.println("****************Menu**************");
        System.out.println("\t\t1.注册");
        System.out.println("\t\t2.登录");
        System.out.println("\t\t3.幸运抽奖");
        System.out.println("\t\t4.看小故事");
        System.out.println("\t\t5.退出系统");
        System.out.println("*****************************************");
        System.out.println("\n请选择菜单:");
        int i = input.nextInt();
        switch (i) {
           case 1:
               login();break;
           case 2:
               zhuce();break;
           case 3:
               choujiang();break;
           case 4:
               xiaogushi();break;
           case 5:
               System.out.println("退出系统");
           default:
               System.out.println("输入错误！");
               returnMain();
               break;
           }
       }
        
   private static void zhuce() {
           Scanner input=new Scanner(System.in);
           System.out.println("请输入用户名：");
           String name=input.next();
           System.out.println("请输入密码：");
           String password=input.next();             
           if(name.equals("李四")&&password.equals("123456")) {
               System.out.println("注册成功");
           }else {
               System.out.println("注册失败");
           }
           returnMain();
       }
    
    private static void login() {
       Scanner input=new Scanner(System.in);
       System.out.println("请输入用户名：");
       String name=input.next();
       System.out.println("请输入密码：");
       String pwd=input.next();
       if(name.equals("李四")&&pwd.equals("123456")) {
           System.out.println("登录成功");
       }else {
           System.out.println("登录失败");
       
       }
       returnMain();
   }
    private static void choujiang() {
           Scanner input=new Scanner(System.in);
           Random r=new Random();
           System.out.println("请输入一个四位数：");
           int x=input.nextInt();
           int y=r.nextInt(10);
           if(x/100%10==y) {
               System.out.println("幸运会员");
           }else {
               System.out.println("很遗憾您不是幸运会员");
           }
           returnMain();
           
       }
     private static void xiaogushi() {
           Scanner input=new Scanner(System.in);
           System.out.println("请选择您要看的小故事：1.格林童话");
           int z=input.nextInt();
           switch(z) {
           case 1:
               System.out.println("格林童话");
           default:
               System.out.println("没有该图书！");
           }
           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。 [必做题]

package demo;
import java.util.*;
public class lianxi {
	public static void main(String[] args) {
        int sum=1;
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入一个整数：");
        int k = sc.nextInt();
        for (int i = 1; i <= k; i++) {
            sum=sum*i;
        }
        System.out.println(k+"的阶乘为："+sum);
    }
}

　　

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package demo;

public class lianxi {
	public static void main(String[] args) {
        near(2020);
    }
        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");
                }
        }

}