第八周作业

1:完善menu

package di;

import java.util.Scanner;
public class ci {
public static void main(String[] args) {

               Scanner input = new Scanner(System.in);
              String A = "y";
         do {
               System.out.println("*************管 理 系 统************");
               System.out.println("\t\t1.注册");
               System.out.println("\t\t2.登录");
               System.out.println("\t\t3.抽奖");
               System.out.println("*****************************************");
               System.out.println("\n请选择菜单:");
               int choice = input.nextInt();
              int random = (int) (Math.random() * 4000);
              switch (choice) {
               case 1:
                         System.out.println("购物管理系统>注册");
                        System.out.println("请填写个人注册信息:");
                       System.out.print("请输入用户名:");
                       String name = input.next();
                       System.out.print("请输入密码:");
                      String pwd = input.next();
                      System.out.println("\n注册成功!请您记住您的会员卡号:");
                      System.out.println("用户名\t密码\t会员卡号");
                      System.out.println(name + "\t" + pwd + "\t" + random);
                break;
               }
         System.out.println("是否继续(y / n ):");
          A = input.next();
        } while (A.equals("y"));
       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 di;
 
 
public class ci {
        public static int jc(int a){
            int sum=1;
            for (int i = 1; i <=a; i++) {
                sum*=a;
                 
                 
            }
            return sum;
        }
        public static void main(String[] args) {
            System.out.println(jc(6));
        }
}

3.编写一个方法，判断该年份是平年还是闰年

package di;
 
 
public class ci {
    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");
                }
        }
 
}