1:完善menu注册功能,抽奖,看小故事等功能
package demo01; import java.util.*; public class demo001 { 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("***************************"); System.out.println("请选择"); int i = input.nextInt(); switch (i){ case 1: login(); break; case 2: zhuce(); break; case 3: choujiang(); break; case 4: story(); break; case 5: returnmain(); break; } } public static void login() { Scanner input = new Scanner(System.in); System.out.println("输入用户姓名"); String uname=input.next(); System.out.println("输入密码"); String upwd=input.next(); if(uname.equals("zs")&& upwd.equals("12321")){ System.out.println("登录成功"); }else{ System.out.println("登录失败"); } returnmain(); } public static void zhuce(){ Scanner input = new Scanner(System.in); System.out.println("注册姓名"); String zname=input.next(); System.out.println("注册密码"); String zpwd=input.next(); System.out.println("注册成功!"); returnmain(); } public static void choujiang(){ Random r=new Random (); Scanner input=new Scanner(System.in); System.out.println("请输入四位会员号"); int huiyuan=input.nextInt(); int bai=huiyuan/100%10; int lucky=r.nextInt(10); if(bai==lucky){ System.out.println("您是幸运会员"); }else{ System.out.println("您不是幸运会员"); } returnmain(); } public static void story(){ Scanner input =new Scanner(System.in); System.out.println("请选择小故事:1 2 3 4返回菜单"); int i=input.nextInt(); switch (i) { case 1: gs1(); break; case 2: gs2(); break; case 3: gs3(); break; case 5: returnmain(); } returnmain(); } public static void gs1(){ System.out.println("故事1"); } public static void gs2(){ System.out.println("故事二"); } public static void gs3(){ System.out.println("故事三"); } 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 demo01; import java.util.*; public class demo001 { public static void main(String[] args) { int sum=1; Scanner jc = new Scanner(System.in); System.out.println("请输入一个整数:"); int k = jc.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。
package demo01; import java.util.*; public class demo001 { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("请输入一个年份:"); long year = input.nextLong(); if((year%4==0 && year%100!=0) || year%400==0 ){ System.out.println(year+"年是闰年!"); }else{ System.out.println(year+"年不是闰年!"); } } }