1.完善menu注册功能,抽奖,看小故事等功能
package mm; import java.util.Random; import java.util.Scanner; public class yn { 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: zc(); break; case 3: cj(); break; case 4: story(); break; case 5: tc(); break; } } public static void tc() { System.out.println("谢谢使用"); } public static void story() { Scanner input = new Scanner(System.in); System.out.println("请选择想看的故事:"); System.out.println("1.白雪公主"); System.out.println("2.小红帽"); int m = input.nextInt(); switch (m) { case 1: System.out.println("白雪公主"); break; case 2: System.out.println("小红帽"); break; } returnMain(); } private static void cj() { 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 n = r.nextInt(10); if (x / 100 % 10 == n) { System.out.println("恭喜你中奖啦"); } else { System.out.println("谢谢参与"); } returnMain(); } private static void zc() { 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 mima = input.next(); System.out.println("注册成功"); returnMain(); } private static void login() { Scanner input = new Scanner(System.in); System.out.println("请输入用户名"); String uname = input.next(); System.out.println("请输入密码"); String upwd = input.next(); if (uname.equals("nnn") && upwd.equals("568")) { 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"); } } }
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 mm; public class yn { public static int jc(int x){ int sum=1; for(int i=1;i<=x;i++){ sum*=i; } return sum; } public static void main(String[] args) { System.out.println(jc(5)); } }
3.编写一个方法,判断该年份是平年还是闰年。
package mm; public class yn { public static void main(String[] args) { year(2016); } private static void year(int a){ if(a%4==0||a%100!=0&&a%400==0){ System.out.println(a+"年是闰年"); }else{ System.out.println(a+"年不是闰年"); } } }