JAVA作业总结
目录：
- 前言
- 设计与分析
- 踩坑心得
- 主要困难以及改进建议
- 总结
一、前言
1.第四次作业相对于后面的两次题目来说比较简单，题目代码量少，解题思路简单，涉及的类少，运用了Java中的数学类math使用了abs()方法，考察点为Java语法的基本运用。
2.第五次 作业难度上升，加深了我对Java的进一步了解，也为后续的题目集提供了参考思路。在完成作业后，需要进行充分的测试来验证程序的正确性。可以考虑边界条件、异常输入等情况，确保程序能够正确处理各种情况。主要考察异常情况处理运用
3.第六次作业难度比第五次作业难度难度低，将程序模块化，使得每个模块负责特定的功能。增加了菜的口味处理。
二、设计与分析
1.菜单计价程序-2
import java.util.Scanner;
public class Main
{
public static void main(String [] args)
{
Scanner input = new Scanner(System.in);
Menu menu= new Menu();
Order order=new Order();
String dishInfo;
String dishName;
int i = 0;
int b = 0,c = 0;
dishInfo=input.nextLine();
while (dishInfo!=null&&!dishInfo.equals("end"))
{
String[] news=dishInfo.split(" ");
int flag=0;
if(news.length==2&&!news[1].equals("delete"))
{
int unit_price=0;
dishName=news[0];
unit_price=Integer.parseInt(news[1]);
menu.addDish(dishName,unit_price);
}
if(news.length==4)
{
int orderNum=0;
int portion=0;
int count1=0;
dishName=news[1];
orderNum=Integer.parseInt(news[0]);
portion=Integer.parseInt(news[2]);
count1=Integer.parseInt(news[3]);
if(menu.searchDish(dishName,menu.dishes)!=null)
{
order.addARecord(orderNum,dishName,portion,count1,menu.dishes);
System.out.println(order.records[i].orderNum+" "+order.records[i].d.name+" "+order.records[i].getPrice());
i++;
}
else
{
flag=1;
}
if(flag==1)
{
System.out.println(dishName+" does not exist");
}
}
if(news[1].equals("delete"))
{
b = Integer.parseInt(news[0]);
c += order.delARecordByOrderNum(b);
}
dishInfo=input.nextLine();
}
System.out.println(order.getTotalPrice()-c);
}
}
class Dish{
String name;
int unit_price;
public Dish(String name, int unit_price)
{
this.name=name;
this.unit_price=unit_price;
}
public Dish()
{
this.name = " ";
this.unit_price = 0;
}
public int getPrice(int portion)
{
double price = unit_price*(portion+1)/2.0;
return(int) Math.round(price);
}
}
class Menu {
Dish[] dishes=new Dish[20];
static int i = 0;
static int count=0;
public Menu()
{
}
public Menu(String dishName,int unit_price)
{
dishes[i++]=new Dish( dishName, unit_price);
}
void addDish(String dishName,int unit_price)
{
dishes[i++]=new Dish(dishName,unit_price);
}
Dish searchDish(String dishName,Dish[] dishes)
{
int j=0;
count=i;
for(j=count-1;j>=0;j--)
{
if(dishes[j].name.equals(dishName))
return dishes[j];
}
return null;
}
}
class Record
{
int orderNum;
Dish d= new Dish();
int portion,amount;
static int count=0;
public Record()
{
}
public Record(int orderNum,Dish d, int portion,int amount)
{
this.orderNum = orderNum;
this.d = d;
this.portion = portion;
this.amount= amount;
}
public int getPrice()
{
return d.getPrice(portion)*amount;
}
}
class Order
{
Record[] records=new Record[100];
static int count=0;
int getTotalPrice() {
int totalPrice = 0;
for (int i = 0; i < count; i++) {
totalPrice += records[i].getPrice();
}
return totalPrice;
}
void addARecord(int orderNum, String dishName, int portion, int amount, Dish[] dishes)
{
Menu menu = new Menu();
Dish d = menu.searchDish(dishName, dishes);
if(d != null)
{
records[count++] = new Record(orderNum, d, portion, amount);
}
}
int delARecordByOrderNum(int orderNum)
{
if(orderNum<=0||orderNum>count)
{
System.out.println("delete error;");
return 0;
}
else
{
return records[orderNum-1].getPrice();
}
}
}
此题有些问题，有一个测试点过不了，此题设计了四个类，Dish类：该类表示菜品，包括菜品名称(name)和单价(unit_price)，用了两个构造函数，一个用于初始化菜品名称和单价，另一个为空构造函数。getPrice方法用于计算该菜品在指定份数时的价格。Menu类：该类表示菜单，包括菜品数组dishes。还有添加菜品的方法addDish和查找菜品的方法searchDish。Record类：该类表示订单记录，包括订单号(orderNum)、菜品(dish)、份数(portion)和数量(amount)。用了一个构造函数和getPrice方法用于计算该订单记录的价格。Order类：该类表示订单，包括订单记录数组records。还有获取订单总价的方法getTotalPrice和添加/删除订单记录的方法addARecord和delARecordByOrderNum。
类图
2.菜单计价程序-3
import java.util.Calendar;
import java.util.Scanner;
public class Main
{
public static void main(String [] args)
{
Scanner input = new Scanner(System.in);
Menu menu= new Menu();
Table[] tables=new Table[1000];
int tablecount=0,ordercount=0;
String dishInfo;
String dishName;
Dish df;
int i = 0;
int a1=0,a2=0,a3=0;
int b = 0,c = 0;
while (true)
{
dishInfo=input.nextLine();
String[] news=dishInfo.split(" ");
if(dishInfo.equals("end"))
break;
if(news.length==2)
{
if(news[1].equals("delete"))
{
b = Integer.parseInt(news[0]);
c += tables[tablecount].order.delARecordByOrderNum(b);
tables[tablecount].tableprice-=c;
}
else{
int unit_price=0;
dishName=news[0];
unit_price=Integer.parseInt(news[1]);
menu.addDish(dishName,unit_price);
}
}
else if(news.length==4)
{
if(news[0].equals("table"))
{
tablecount++;
ordercount=0;
tables[tablecount] = new Table();
tables[tablecount].gettableTime(dishInfo);
System.out.println("table " + tablecount+": ");
}
else{
int orderNum=0;
int portion=0;
int count1=0;
dishName=news[1];
orderNum=Integer.parseInt(news[0]);
portion=Integer.parseInt(news[2]);
count1=Integer.parseInt(news[3]);
if(menu.searchDish(dishName,menu.dishes)!=null)
{
tables[tablecount].order.addARecord(orderNum,dishName,portion,count1,menu.dishes);
System.out.println(tables[tablecount].order.records[i].orderNum+" "+tables[tablecount].order.records[i].d.name+" "+tables[tablecount].order.records[i].getPrice());
tables[tablecount].tableprice +=tables[tablecount].order.records[i].getPrice();
i++;
}
ordercount++;
if(menu.searchDish(dishName,menu.dishes)==null)
{
System.out.println(dishName+" does not exist");
}
}
}
else if(news.length==5)
{
a1 = Integer.parseInt(news[1]);
a2 = Integer.parseInt(news[3]);
a3 = Integer.parseInt(news[4]);
tables[tablecount].order.addARecord( a1, news[2], a2, a3,menu.dishes);
df = menu.searchDish(news[2],menu.dishes);
if (df != null) {
tables[tablecount].order.records[i].d.unit_price = df.unit_price;
int d = tables[tablecount].order.records[i].getPrice();
System.out.println(news[1] + " table " + tables[tablecount].tablenumber + " pay for table " + news[0] + " " + d);
tables[tablecount].tableprice += d;
}
ordercount++;
}
}
for(int j = 1;j<tablecount+1;j++)
{
tables[j].getfinalPrice();
}
}
}
class Dish{
String name;
int unit_price;
public Dish(String name, int unit_price)
{
this.name=name;
this.unit_price=unit_price;
}
public Dish()
{
this.name = " ";
this.unit_price = 0;
}
public int getPrice(int portion)
{
double price = unit_price*(portion+1)/2.0;
return(int) Math.round(price);
}
}
class Menu {
Dish[] dishes=new Dish[20];
static int i = 0;
static int count=0;
public Menu()
{
}
public Menu(String dishName,int unit_price)
{
dishes[i++]=new Dish( dishName, unit_price);
}
void addDish(String dishName,int unit_price)
{
dishes[i++]=new Dish(dishName,unit_price);
}
Dish searchDish(String dishName,Dish[] dishes)
{
int j=0;
count=i;
for(j=count-1;j>=0;j--)
{
if(dishes[j].name.equals(dishName))
return dishes[j];
}
return null;
}
}
class Record
{
int orderNum;
Dish d= new Dish();
int portion,amount;
static int count=0;
public Record()
{
}
public Record(int orderNum,Dish d, int portion,int amount)
{
this.orderNum = orderNum;
this.d = d;
this.portion = portion;
this.amount= amount;
}
public int getPrice()
{
return d.getPrice(portion)*amount;
}
}
class Order
{
Record[] records=new Record[100];
static int count=0;
int getTotalPrice() {
int totalPrice = 0;
for (int i = 0; i < count; i++) {
totalPrice += records[i].getPrice();
}
return totalPrice;
}
void addARecord(int orderNum, String dishName, int portion, int amount, Dish[] dishes)
{
Menu menu = new Menu();
Dish d = menu.searchDish(dishName, dishes);
if(d != null)
{
records[count++] = new Record(orderNum, d, portion, amount);
}
}
int delARecordByOrderNum(int orderNum)
{
if(orderNum<=0||orderNum>count)
{
System.out.println("delete error;");
return 0;
}
else
{
return records[orderNum-1].getPrice();
}
}
}
class Table
{
int tablenumber;
String tabletime;
int year;
int month;
int day;
int hour;
int minute;
int miao;
int week;
long tableprice;
double discount=0;
Order order=new Order();
void gettableTime(String tabletime){
this.tabletime = tabletime;
processtime();
getdiscountPrice();
}
void processtime()
{
String []tt=tabletime.split(" ");
tablenumber = Integer.parseInt(tt[1]);
String[] tt1 = tt[2].split("/");
String[] tt2 = tt[3].split("/");
year = Integer.parseInt(tt1[0]);
month = Integer.parseInt(tt1[1]);
day = Integer.parseInt(tt1[2]);
hour = Integer.parseInt(tt2[0]);
minute = Integer.parseInt(tt2[1]);
miao = Integer.parseInt(tt2[2]);
Calendar calendar = Calendar.getInstance();
calendar.set(year, (month-1), day);
week = calendar.get(Calendar.DAY_OF_WEEK);
if(week==1)
week = 7;
else
week--;
}
void getdiscountPrice()
{
if(week>=1&&week<=5)
{
if(hour>17&&hour<20) discount=0.8F;
else if(hour==17&&minute==00&&miao==00) discount=0.8F;
else if(hour==20&&minute<30) discount=0.8F;
else if(hour==20&&minute==30&&miao==0) discount=0.8F;
else if(hour>=11&&hour<=13||hour==10&&minute>=30) discount=0.6F;
else if(hour==14&&minute<30) discount=0.6F;
else if(hour==14&&minute==30&&miao==0) discount=0.6F;
}
else
{
if(hour>=10&&hour<=20) discount= 1.0F;
else if(hour==9&&minute>=30)discount= 1.0F;
else if(hour==21&&minute<30||hour==21&&minute==30&&miao==0) discount= 1.0F;
}
}
void getfinalPrice()
{
if(discount>0){
tableprice = Math.round(tableprice*discount);
System.out.println("table " + tablenumber + ": " + tableprice);
}else {
System.out.println("table " + tablenumber + " out of opening hours");
}
}
}
此题还有一部分测试点没过，我定义了菜品类 Dish，菜单类 Menu，记录类 Record，订单类 Order，以及餐桌类 Table。其中，菜菜单类用于存储菜品信息并提供搜索功能，记录类用于记录订单中的菜品信息和价格，订单类用于管理订单信息，餐桌类用于处理时间和折扣计算，并最终得出账单金额。程序的大致流程为，首先输入菜品信息和订单信息，并将菜品信息存储在菜单中。然后根据输入的命令处理订单信息，包括添加菜品记录、删除菜品记录等操作。最后处理时间信息，计算折扣，并计算最终账单金额。对时间和折扣的处理，通过 Calendar 类来获取具体的日期和星期信息，并根据具体的时间段计算折扣。
圈复杂度：
菜单计价程序-4
此题我对异常情况处理的不太好，也没有针对异常情况处理设置类，在针对输入菜单记录的语句处理有问题，导致菜单记录输入没有输出。
类图
圈复杂度：
菜单计价程序-5
import java.util.Scanner;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;
public class Main
{
public static void main(String[] args) throws ParseException {
Menu menu = new Menu();
Scanner input = new Scanner(System.in);
String dishInfo = input.nextLine();
while (!dishInfo.startsWith("table"))
{
String[] news = dishInfo.split(" ");
if (news.length == 2)
{
String dishname = news[0];
int unit_price = Integer.parseInt(news[1]);
if (menu.searchDish(dishname) == null)
{
menu.addDish(dishname, unit_price);
}
}
else if (news.length == 4 && dishInfo.endsWith("T"))
{
String dishname = news[0];
String dishtype = news[1];
int unit_price = Integer.parseInt(news[2]);
Map<String, String> map = new HashMap<String, String>() {
{
put("川菜", "Chuan");
put("晋菜", "Jin");
put("浙菜", "Zhe");
}
};
DishType dishType = DishType.valueOf(map.get(dishtype));
if (menu.searchDish(dishname) == null) {
menu.addDish(dishname, unit_price, dishType);
}
}
else
{
System.out.println("wrong format");
}
dishInfo = input.nextLine();
}
ArrayList<Table> tables = new ArrayList<>();
ArrayList<String> names = new ArrayList<>();
int tablecount = 0;
String name = null;
String phone = null;
Date date = null;
Date time = null;
boolean islegaltime = true;
boolean islegalnews = true;
String orderLine = dishInfo;
while (!orderLine.equals("end")) {
String[] orderInfo = orderLine.split(" ");
if (orderLine.startsWith("table")) {
islegalnews = true;
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd");
SimpleDateFormat timeFormat = new SimpleDateFormat("HH/mm/ss");
tablecount = Integer.parseInt(orderInfo[1]);
name = orderInfo[3];
phone = orderInfo[4];
try {
date = dateFormat.parse(orderInfo[5]);
time = timeFormat.parse(orderInfo[6]);
}
catch (Exception e)
{
islegalnews = false;
System.out.println("wrong format");
orderLine = input.nextLine();
continue;
}
String regex = "^1(80|81|89|33|35|36)\\d{8}$";
Table table = new Table(tablecount, name, phone, date, time);
tables.add(table);
if (name.length() > 10 || !phone.matches(regex)) {
islegalnews = false;
System.out.println("wrong format");
orderLine = input.nextLine();
continue;
}
if (!names.contains(name)) {
names.add(name);
}
if (table.getdiscount(true) == 0) {
islegaltime = false;
System.out.println("table " + table.tablecount + " out of opening hours");
} else {
System.out.println("table " + table.tablecount + ": ");
}
} else {
if (islegalnews) {
int orderNum;
try {
orderNum = Integer.parseInt(orderInfo[0]);
} catch (Exception e) {
System.out.println("wrong format");
orderLine = input.nextLine();
continue;
}
if (orderLine.endsWith("delete")) {
if (!tables.get(tablecount - 1).delRecordByOrderNum(orderNum)) {
System.out.println("delete error");
}
} else {
if (orderInfo.length == 4) {
String dishName = orderInfo[1];
int portion = Integer.parseInt(orderInfo[2]);
int amount = Integer.parseInt(orderInfo[3]);
Dish dish = menu.searchDish(dishName);
if (dish == null) {
System.out.println(dishName + " does not exist");
orderLine = input.nextLine();
continue;
}
Record record = new Record(tablecount, orderNum, dish, portion, amount);
tables.get(tablecount - 1).addRecord(record);
if (islegaltime) {
System.out.println(record.print(tablecount));
}
} else if (orderInfo.length == 5) {
String dishName = orderInfo[1];
int stylenum = Integer.parseInt(orderInfo[2]);
int portion = Integer.parseInt(orderInfo[3]);
int amount = Integer.parseInt(orderInfo[4]);
Dish dish = menu.searchDish(dishName);
if (dish == null) {
System.out.println(dishName + " does not exist");
orderLine = input.nextLine();
continue;
}
Record record = new Record(tablecount, orderNum, dish, stylenum, portion, amount);
tables.get(tablecount - 1).addRecord(record);
if (islegaltime) {
System.out.println(record.print(tablecount));
}
} else if (orderInfo.length == 6) {
int othernumber = Integer.parseInt(orderInfo[1]);
String dishName = orderInfo[2];
int stylenum = Integer.parseInt(orderInfo[3]);
int portion = Integer.parseInt(orderInfo[4]);
int amount = Integer.parseInt(orderInfo[5]);
Dish dish = menu.searchDish(dishName);
if (dish == null) {
System.out.println(dishName + " does not exist");
orderLine = input.nextLine();
continue;
}
Record record1 = new Record(othernumber, orderNum, dish, stylenum, portion, amount);
Record record2 = new Record(othernumber, orderNum, dish, stylenum, 0, amount);
tables.get(tablecount - 1).addRecord(record1);
tables.get(othernumber - 1).addRecord(record2);
if (islegaltime) {
System.out.println(record1.print(tablecount));
}
} else {
System.out.println("wrong format");
}
}
}
}
orderLine = input.nextLine();
}
input.close();
for (Table table : tables) {
if (table.flag && table.getTotalPrice() != 0) {
System.out.println(table.printInfo());
}
}
names.sort(new Comparator<String>() {
public int compare(String order1, String order2) {
return order1.compareTo(order2);
}
});
for (String costumName : names) {
int sum = 0;
String costumPhone = null;
for (Table table : tables) {
if (table.name.equals(costumName)) {
sum += table.getCheckedPrice();
costumPhone = table.phone;
}
}
if (sum != 0) {
System.out.println(costumName + " " + costumPhone + " " + sum);
}
}
}
}
enum DishType {
Chuan,
Jin,
Zhe,
}
class Dish {
String name;
int unit_price;
DishType type;
public Dish(String name, int unit_price, DishType type) {
this.name = name;
this.unit_price = unit_price;
this.type = type;
}
public Dish()
{
this.name = " ";
this.unit_price = 0;
}
public Dish(String name, int unit_price) {
this.name = name;
this.unit_price = unit_price;
}
public String toString() {
return name;
}
}
class Menu {
public ArrayList<Dish> dishes = new ArrayList<>();
public Dish searchDish(String dishName) {
for (Dish dish : dishes) {
if (dish.name.equals(dishName)) {
return dish;
}
}
return null;
}
void addDish(String dishName, int unit_price) {
dishes.add(new Dish(dishName, unit_price));
}
void addDish(String dishName, int unit_price, DishType type) {
dishes.add(new Dish(dishName, unit_price, type));
}
}
class Record {
int orderNum;
Dish dish=new Dish();
int portion, amount;//份量，份额;
int stylenum;
boolean flag;
int othernumber;
public Record(int othernumber, int orderNum, Dish dish, int portion, int amount) {
this.orderNum = orderNum;
this.dish = dish;
this.portion = portion;
this.amount = amount;
this.stylenum = -1;
this.flag = true;
this.othernumber = othernumber;
}
public Record(int othernumber, int orderNum, Dish dish, int stylenum, int portion, int amount) {
this.orderNum = orderNum;
this.dish = dish;
this.portion = portion;
this.amount = amount;
this.stylenum = stylenum;
this.flag = check_stylenum();
this.othernumber = othernumber;
}
int getPrice() {
if (!flag)
return 0;
double price = dish.unit_price*amount*(portion+1)/2.0;
return(int) Math.round(price);
}
int getCheckedPrice(double discount) {
return (int) Math.round(getPrice() * discount);
}
boolean check_stylenum() {
switch (dish.type) {
case Chuan:
if (stylenum > 5 || stylenum < 0)
{
return false;
} else {
return true;
}
case Jin:
if (stylenum > 4 || stylenum < 0)
{
return false;
} else {
return true;
}
case Zhe:
if (stylenum > 3 || stylenum < 0) {
return false;
} else {
return true;
}
default:
return true;
}
}
public String print(int tablecount) {
if (flag == false) {
switch (dish.type) {
case Chuan:
return "spicy num out of range :" + stylenum;
case Jin:
return "acidity num out of range :" + stylenum;
case Zhe:
return "sweetness num out of range :" + stylenum;
default:
return null;
}
} else
{
if (othernumber == tablecount)
{
return orderNum + " " + dish.toString() + " " + getPrice();
}
return orderNum + " table " + tablecount + " pay for table " + othernumber + " " + getPrice();
}
}
public String toString() {
return "Record [orderNum=" + orderNum + ", dish=" + dish + ", portion=" + portion + ", amount=" + amount
+ ", stylenum=" + stylenum + ", flag=" + flag + ", othernumber=" + othernumber + "]";
}
}
class Table {
ArrayList<Record> records = new ArrayList<>();
int tablecount;
String name;
String phone;
Date date;
Date time;
boolean flag;
public Table(int tablecount, String name, String phone, Date date, Date time) {
this.name = name;
this.phone = phone;
this.date = date;
this.time = time;
this.tablecount = tablecount;
this.flag = true;
}
double getdiscount(boolean Special) throws ParseException {
double discount = 0;
SimpleDateFormat sdfTime = new SimpleDateFormat("HH:mm");
Calendar cal = Calendar.getInstance();
cal.setTime(date);
int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
// 营业时间
if (dayOfWeek == 1 || dayOfWeek == 7) {
if (time.after(sdfTime.parse("9:29")) && time.before(sdfTime.parse("21:31"))) {
discount = 1;
}
} else {
if (time.after(sdfTime.parse("16:59")) && time.before(sdfTime.parse("20:31"))) {
if (Special) {
discount = 0.7;
} else {
discount = 0.8;
}
} else if (time.after(sdfTime.parse("10:29")) && time.before(sdfTime.parse("14:31"))) {
if (Special) {
discount = 0.7;
} else {
discount = 0.6;
}
}
}
if (discount == 0) {
flag = false;
}
return discount;
}
int getTotalPrice() {
int sum = 0;
for (Record record : records) {
sum += record.getPrice();
}
return sum;
}
int getCheckedPrice() throws ParseException {
int sum = 0;
for (Record record : records) {
if (record.stylenum != -1) {
sum += record.getCheckedPrice(getdiscount(true));
} else {
sum += record.getCheckedPrice(getdiscount(false));
}
}
return sum;
}
String getAvestylenum(DishType type) {
String[] spicy = { "不辣", "微辣", "稍辣", "辣", "很辣", "爆辣" };
String[] acidity = { "不酸", "微酸", "稍酸", "酸", "很酸" };
String[] sweetness = { "不甜", "微甜", "稍甜", "甜" };
double sum = 0;
double num = 0;
for (Record record : records) {
if (record.dish.type == type) {
if (record.flag && tablecount == record.othernumber) {
num += record.amount;
sum += record.stylenum * record.amount;
}
}
}
if (num == 0) {
return "";
}
int ave = (int) Math.round(sum / num);
switch (type) {
case Chuan:
return " 川菜 " + (int) num + " " + spicy[average];
case Jin:
return " 晋菜 " + (int) num + " " + acidity[average];
case Zhe:
return " 浙菜 " + (int) num + " " + sweetness[average];
default:
return null;
}
}
void addRecord(Record record) {
records.add(record);
}
public String printInfo() throws ParseException {
String chuan = getAvestylenum(DishType.Chuan);
String jin = getAvestylenum(DishType.Jin);
String zhe = getAvestylenum(DishType.Zhe);
if (chuan == "" && jin == "" && zhe == "") {
return "table " + tablecount + ": " + getTotalPrice() + " " + getCheckedPrice() + " ";
} else {
return "table " + tablecount + ": " + getTotalPrice() + " " + getCheckedPrice() + chuan + jin + zhe;
}
}
boolean delRecordByOrderNum(int orderNum) {
return records.removeIf(record -> record.orderNum == orderNum);
}
Record findRecordByOrderNum(int orderNum) {
for (Record record : records) {
if (record.orderNum == orderNum) {
return record;
}
}
return null;
}
}
整个程序设计了菜品类、菜单类、记录类、桌子类。菜品类包括菜品名称、单价、菜系类型等属性和方法，用于表示各种菜品信息。菜单类包括菜品列表和相关操作方法，用于管理所有菜品的增删改查操作。记录类包括订单号、菜品信息、份数、数量等属性和方法，用于表示顾客点菜的记录信息。桌子类包括桌号、顾客姓名、联系方式、就餐日期、就餐时间、订单记录等属性和方法，用于表示每张桌子的就餐信息和订单记录。
类图:
圈复杂度
期中考试题目：
期中考试的题目总体难度不高，上课的时候也分析过此类问题。考试的时候代码出现报错，虽然能立马反应出来是哪里的问题但是修改花的时间较长，导致后来都i没有多长时间去完成别的题目。平常完成作业，敲代码的速度也比较慢，没有在规定的时间内完成题目作答。后来考试结束后重新看了题目。成功完成，考试的题目难度不大，但是由于我队继承多态的问题不熟练，再加上敲代码的速度慢，不能及时完成。
三、踩坑心得
1.菜单计价程序2，刚开始我没有考虑到输入多个重复菜时以第一个出现的菜单为主，然后在处理删除记录的时候也没有考虑删除记录相同的情况，导致代码报错，重新设计了删除记录的方法后，问题大致解决，但仍然存在问题。
我的错误示例：
错误的删除记录方法设计
int delARecordByOrderNum(int orderNum)
{
int i=0;
if(orderNum<0)
{
return 0;
}
for (i=0;i< count;i++)
{
if(records[i].orderNum==orderNum)
return records[i].getPrice();
}
System.out.println("delete error");
return 0;
}
}
设计导致错误的原因可能是方法名表明的是删除操作，但实际上返回的是被删除记录的价格，这样设计容易引起误解。然后删除记录，应该在找到符合条件的记录后进行删除操作，对于订单号小于0的情况，直接返回0，没有给出具体的错误信息或提示，这样不太利于调试和排查问题。
改进后的删除记录的方法设计：
int delARecordByOrderNum(int orderNum)
{
if(orderNum<0||orderNum>count)
{
System.out.println("delete error;");
return 0;
}
else
{
return records[orderNum-1].getPrice();
}
}
这样设计对于订单号小于0或大于记录总数的情况进行了判断，避免了数组越界的可能性。
仍需要改进的是通过返回价格来实现删除操作，并没有进行记录的删除，可能导致误解。缺乏详细的错误处理机制，只是简单地打印了一条错误信息，并返回了0。
2.菜单计价程序3
多次修改仍然存在问题，后来补练，仍然存在问题。测试案例七偶尔会出现运行超时的情况。问题是，当删除相同的记录后，题目不在输出，我想极有可能是我删除记录的方法设计的还有问题。
3.菜单计价程序4
对异常情况处理不太熟悉，不太会使用使用try...catch语句可以进行异常处理，使用try块，异常被抛出时，使用catch块来处理这些异常。
4.菜单计价程序5
此题存在输入多道相同的菜以最后一次输入为准的问题，然后在计算菜价的时候也存在问题，所以部分测试点没过，具体是哪个问题我没有找出来，这次在运用了异常处理机制，对异常情况进行处理。
5.期中考试
求圆的周长或者面积这种问题是最基础的问题，在之前课堂测试的时候有写过，能做出来，但没有按照题目要求，后续的题目也是，设计类的时候没有按照题目给的类图设计类和类的方法。
四、主要困难及改进建议
总的来说我的代码可复用性不高，出现新的迭代，大多需要重新设计类和类的方法，否则会出现很多错误。对代码应该进行适当的模块化，将功能相近的代码封装成方法，提高代码的可读性和可维护性，代码记得注释吧，当时菜单计价程序写的什么没怎么注释，再加上时间拉的很长，每天登进pta看会，写点，时间久了就忘记了，经常要上下翻翻看看。出现输出结果不是理想结果时，在知道可能是哪个方法，哪一不符出错的情况下，找错误的代码都要找半天，排查起来很麻烦。给别人看，阅读起来也很困难。
五、总结
这是本学期Java第二阶段的学习，能看到自己获得了知识，但更多的是自己的不足，而且不足之处很明显。学习的东西虽然基础，但是掌握却需要大量联系。从最初适应Java语言变成灵活运用Java语言，再到后面运用多个类编写程序，还有很长的路需要自己去一步步践行。作为初学者，发现还有许多东西需要去掌握：
1.基础语法的巩固，在进行Java编程中，时常脱离不出C语言的习惯，导致出现语法错误，甚至不记得如何进行编写，这需要在练习中，不要只会对之前自己写的代码复制粘贴，还要留意写法。
2.多学习使用eclipse，这个编译软件很好用，功能很多，自动报错的功能对于代码的修改很有帮助，写pta不能只在那上面写代码，灵活运用eclipse对自己编写修改代码很有帮助。当然idea也好用，不过eclipse用习惯了。
3.不同类之间的关系，许多时候正是不知如何进行将类互相呼应，导致代码亢长，产生垃圾代码，这不利于学习；当能够了解，并运用类与类之间的关系，则能解决大多数问题。
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