第八周作业

1:完善menu注册功能,抽奖,看小故事等功能

package work8;
import java.util.*;
public class Menu {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//完善menu注册功能,抽奖,看小故事等功能
	      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:
            register();
            break;
        case 3:
            choujiang();
            break;
        case 4:
            kgs();
            break;
        case 5:
            break;
        
        }
    }

    private static void login() {
        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 register(){
        System.out.println("请输入用户名:");
        Scanner input= new Scanner(System.in);
        String line=input.nextLine();
        System.out.println("请输入密码");
        int a =input.nextInt();
        login();
        
    }
    
    private static void choujiang(){
        Random r=new Random();
        int x=r.nextInt(10);
        System.out.println("请输入4位号码:");
        Scanner input=new Scanner(System.in);
        int i= input.nextInt();
        if(x==i%1000/100){
            System.out.println("恭喜你中奖了!");
        }else{
            System.out.println("很遗憾你没有中奖!");
        }
        returnMain();
    }
    
    private static void kgs(){
        System.out.println("从前有座山");
        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 work8;

public class Marrier1 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		// 编写一个方法，求整数n的阶乘，
		Marrier(5);
	}

	public static void Marrier(int i) {
		int Marrier = 1;
		for (int j = 1; j <= i; j++) {
			Marrier *= j;
		}
		System.out.println(i + "的阶乘为" + Marrier);
	}
}

　　3.编写一个方法，判断该年份是平年还是闰年。

package work8;

public class Marrier2 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		// 编写一个方法，判断该年份是平年还是闰年
		Marrier2(2020);
	}

	public static void Marrier2(int year) {
		if (year % 4 == 0 && year % 100 != 0 || (year % 400 == 0)) {
			System.out.println(year + "是闰年");
		} else {
			System.out.println(year + "不是闰年");
		}
	}
}