标签：分数 输入密码 switch average print sum use index register
package classTest;
import java.util.Scanner;
public class scoreArrangement {
/**
* 选择界面（main）
*/
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String[] name = new String[2];
String[] password = new String[2];
int i = 0;// main函数和register函数里面，数组的下标
while (true) {
System.out.println("选择菜单");
System.out.print("A、注册 B、登陆 C、退出");
String choice = sc.next();
switch (choice) {
case "a":
case "A":
if (name[1] == null) {
System.out.println(name[0] + " " + password[0]);
System.out.println(name[1] + " " + password[1]);
i = register(name, password, i);
break;
} else {
System.out.println("已注册满！");
break;
}
case "b":
case "B":
dengLu(name, password);
break;
case "c":
case "C":
System.out.println("退出成功");
System.exit(-1);
break;
default:
System.out.println("无效输入，重新选择！");
break;
}
}
}
/**
* 注册
*/
public static int register(String[] a, String[] b, int x) {
Scanner sc = new Scanner(System.in);
System.out.print("请输入用户名：");
a[x] = sc.next();
System.out.println("请输入密码：");
b[x] = sc.next();
System.out.println("注册成功，用户名为：" + a[x] + " 密码为：" + b[x]);
x++;
return x;
}
/**
* 登陆
*/
public static void dengLu(String[] a, String[] b) {
Scanner sc = new Scanner(System.in);
int times = 0;
System.out.println(a[0] + " " + b[0]);
System.out.println(a[1] + " " + b[1]);
while (times < 3) {
System.out.print("请输入用户名：");
String name = sc.next();
System.out.println("请输入密码：");
String password = sc.next();
for (int x = 0; x < 2; x++) {
if (name.equals(a[x]) && password.equals(b[x])) {
fenShuGuanLi();
times = 3;
break;
} else {
System.out.println("用户名或者密码不对,重新输入。");
times++;
if (times == 3) {
System.out.println("3次输入错误，退出！");
// System.exit(-1);如果需要停止运行，加上此行代码。
}
break;
}
}
}
}
/**
* 分数管理
*/
public static void fenShuGuanLi() {
String[] name = new String[100];
double[] score = new double[100];
Scanner sc = new Scanner(System.in);
int index = 1;
int number = 0;// 学生姓名数组下标
while (index == 1) {
System.out.println("输入选择：");
System.out.println("1、录入学生成绩。");
System.out.println("2、修改学生成绩。");
System.out.println("3、删除学生成绩。");
System.out.println("4、查询单个学生成绩。");
System.out.println("5、查询所有学生成绩。");
System.out.println("6、平均成绩。");
System.out.println("7、返回上级菜单。");
int choice = sc.nextInt();
switch (choice) {
case 1:
if(number==99){
System.out.println("数据已满，不能继续录入。");
break;
}
number = luRuFenShu(name, score, number);
break;
case 2:
xiuGaiFenShu(name, score, number);
break;
case 3:
shanChuFenShu(name,score,number);
break;
case 4:
chaXunFenShu(name, score);
break;
case 5:
chaXunAll(name,score,number);
break;
case 6:
average(name,score,number);
break;
case 7:
index = 0;
break;
default:
System.out.println("无效选择，重新输入。");
break;
}
}
}
/**
* 录入分数
*/
public static int luRuFenShu(String[] name, double[] score, int number) {
if (number > 99) {
System.out.println("存储空间不足，不能录入！返回上级菜单。");
return number;
}
// System.out.println("Welcome lurufenshu!");
Scanner sc = new Scanner(System.in);
int index = 0;
while (index == 0) {
System.out.println("请输入学生姓名：");
String userName = sc.next();
name[number] = userName;
System.out.println("请输入学生分数：");
double userScore = sc.nextDouble();
score[number] = userScore;
System.out.println("录入信息成功，是否继续录入？Y/N");
int index1 = 0;
while (index1 == 0) {
String choice = sc.next();
switch (choice) {
case "y":
case "Y":
number++;
index1 = 1;
break;
case "n":
case "N":
number++;
return number;
default:
System.out.println("无效指令，请重新输入：");
break;
}
}
}
return number;
}
/**
* 修改分数
*/
public static void xiuGaiFenShu(String[] name, double[] score, int number) {
System.out.println("请输入学生名字：");
Scanner sc = new Scanner(System.in);
if (name[0] != null) {
String userName = sc.next();
int i = 0;
for (i = 0; i < number; i++) {
if (name[i].equals(userName)) {
System.out.println("请输入修改后的分数：");
score[i] = sc.nextDouble();
System.out.println("修改成功！ " + name[i] + " " + score[i] + "分");
break;
}
}
if (i == number) {
System.out.println("没有该学生信息！");
}
} else {
System.out.println("数据库为空，请先录入数据！");
}
}
/**
* 删除分数
*/
public static int shanChuFenShu(String[]name,double[]score,int number) {
Scanner sc=new Scanner(System.in);
System.out.println("请输入要删除成绩的学生名字：");
String userName=sc.next();
for(int i=0;i<=number;i++){
if(name[i].equals(userName)&&i==99){
System.out.println("删除成功！");
name[i]=null;
score[i]=0;
}else if(name[i].equals(userName)){
System.out.println("删除成功！");
name[i]=name[i+1];
name[i+1]=null;
score[i]=score[i+1];
score[i]=0;
number--;
}
}
return number;
}
/**
* 查询单个分数
*/
public static void chaXunFenShu(String[] name, double[] score) {
System.out.println("请输入学生名字：");
Scanner sc = new Scanner(System.in);
String userName = sc.next();
if (name[0] != null) {
int i = 0;
for (i = 0; i < name.length - 1; i++) {
if (name[i].equals(userName)) {
System.out.println("该学生的成绩是：" + score[i] + "分。");
break;
}
}
if (i == name.length - 1) {
System.out.println("没有该学生信息！");
}
} else {
System.out.println("数据库为空，请先录入成绩！");
}
}
/**
* 查询全部分数
*/
public static void chaXunAll(String[]name,double[]score,int number) {
if (name[0] != null) {
for(int i=0;i<number;i++){
System.out.println(name[i]+"、"+score[i]+"分.");
}
} else {
System.out.println("数据库为空，请先录入成绩！");
}
}
/**
* 求平均分
*/
public static void average(String[]name,double[]score,int number) {
double averageScore=0;
double sum=0;
for(int i=0;i<name.length-1;i++){
sum+=score[i];
}
System.out.println("平均分为："+sum/(number+1));
}
}
标签：分数 输入密码 switch average print sum use index register
原文地址：http://www.cnblogs.com/DavidTom/p/6196161.html
