1.编写一个方法,实现冒泡排序(由小到大),并调用该方法
package java作业; import java.util.Scanner; public class Java1 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); System.out.println("输入5个数:"); int a[] = new int[5]; int b; for (int i = 0; i < a.length; i++) { a[i] = input.nextInt(); } for (int i = 0; i < a.length - 1; i++) { for (int j = i+1; j < a.length; j++) { if (a[i] > a[j]) { b = a[i]; a[i] = a[j]; a[j] = b; } } } for (int i = 0; i < a.length; i++) { System.out.print(a[i]); System.out.print(" "); } System.out.println(); } }
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 java作业; import java.util.Scanner; public class Java1 { /** * @param args */ // TODO Auto-generated method stub public static int jc(int a){ int sum=1; for(int i=1;i<=a;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。[必做题]
package java作业; import java.util.Scanner; public class Java1 { /** * @param args */ // TODO Auto-generated method stub private static void prn() { Scanner input = new Scanner(System.in); System.out.println("请输入年份"); int year = input.nextInt(); if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) { System.out.println("是闰年"); } else { System.out.println("是平年"); } } public static void main(String[] args) { prn(); } }
4.课堂没完成的menu菜单,实现幸运抽奖功能
package java作业; import java.util.Scanner; import java.util.Random; public class Java1 { public static void mainMenu(){ Scanner input=new Scanner(System.in); System.out.println("欢迎使用本系统"); System.out.println("1.登录"); System.out.println("2.注册"); System.out.println("3.幸运抽奖"); System.out.println("4.退出"); System.out.println("请选择"); int i=input.nextInt(); switch(i){ case 1: login(); break; case 2: reg(); break; case 3: lucky(); } } private static void lucky() { // 输入四位会员卡号,如果百位数等于随机数,幸运会员。否则不是。同时也要询问是否返回主菜单 Scanner input=new Scanner(System.in); Random r=new Random(); int luck=r.nextInt(10); System.out.println("输入四位数会员卡号"); int id=input.nextInt(); if (luck==id) { System.out.println("幸运会员"); }else{ System.out.println("不是幸运会员"); } returnMain(); } public static void returnMain(){ Scanner input=new Scanner(System.in); System.out.println("是否返回主菜单?"); if(input.next().equalsIgnoreCase("Y")) mainMenu(); else System.out.println("谢谢使用"); } public static void reg() { // TODO Auto-generated method stub Scanner input=new Scanner(System.in); System.out.println("输入要注册的用户名"); String uname=input.next(); System.out.println("输入注册密码"); String upwd=input.next(); System.out.println("注册成功"); returnMain(); } public 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("ok"); }else{ System.out.println("fail"); } returnMain(); } public static void main(String[] args) { mainMenu(); } }