java第九次作业
1.编写一个方法,实现冒泡排序(由小到大),并调用该方法
import java.util.Scanner; public class px { // 编写一个方法,实现冒泡排序(由小到大),并调用该方法 public static void sort() { Scanner input = new Scanner(System.in); System.out.println("请输入5个数:"); int a[] = new int[5]; int temp; for (int i = 0; i < a.length; i++) { a[i] = input.nextInt(); } for (int i = 0; i < a.length - 1; i++) { for (int j = 0; j < a.length - 1 - i; j++) { if (a[i] > a[i + 1]) { temp = a[i]; a[i] = a[i + 1]; a[i + 1] = temp; } } } System.out.println("----排序后----"); for (int i = 0; i < a.length; i++) { System.out.print(a[i] + " "); } System.out.println(); } public static void main(String[] args) { sort(); } }
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]
public class jc { // 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] public static int jc(int n) { int sum = 1; for (int i = 1; i <= n; i++) { sum *= i; } return sum; } public static void main(String[] args) { System.out.println("5的阶乘为" + jc(5)); } }
3.编写一个方法,判断该年份是平年还是闰年。[必做题]
import java.util.Scanner; public class pd { // 编写一个方法,判断该年份是平年还是闰年。[必做题] public static void decide() { Scanner input = new Scanner(System.in); System.out.println("请输入要判断的年份"); int year = input.nextInt(); if (year % 400 == 0 && year % 100 != 0 || year % 4 == 0) System.out.println("该年为闰年"); else System.out.println("该年为平年"); } public static void main(String[] args) { decide(); } }
4.课堂没完成的menu菜单,实现幸运抽奖功能
package work1; import java.util.Random; import java.util.Scanner; public class menu { 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.退出系统"); System.out.println("请选择:"); int i = input.nextInt(); switch (i) { case 1: login(); break; case 2: register(); break; case 3: luckymember(); break; } } // 返回主菜单 public static void returnMain() { Scanner input = new Scanner(System.in); System.out.println("是否返回主菜单?Y/N"); if (input.next().equalsIgnoreCase("Y")) mainMenu(); else System.out.println("谢谢使用"); } public static void main(String[] args) { mainMenu(); } // 1登录 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 pwd = input.next(); if (uname.equals("admin") && pwd.equals("admin")) System.out.println("成功"); else System.out.println("失败"); returnMain(); } // 2注册 public static void register() { 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 pwd = input.next(); System.out.println("注册成功"); returnMain(); } // 完成3 输入四位会员卡号 如果百位等于随机数,就是幸运会员。询问是否返回主菜单。 public static void luckymember() { Scanner input = new Scanner(System.in); System.out.println("输入四位数的会员号"); int number = input.nextInt(); Random s = new Random(); int m = s.nextInt(); int n = number / 100 % 10; while (true) { if (n > m && n < m) System.out.println("恭喜会员"); else System.out.println("谢谢参与"); break; } returnMain(); } }