我对完成此计划有些犹豫
评估要求我们遵循以下提供的信息，实施RockConcert和TicketHolder类。 TicketHolder类代表为特定音乐会的入场费付费的人。此类TicketHolder类应跟踪其花费以及座位的位置。
给定提供的驱动程序，我已经构造了大多数代码，但是我对如何使用RockConcert :: sellTicket和RockConcert :: getTicket编码方法感到很困惑
下面是代码，
万分感谢！
TicketHolder.h
#ifndef TicketHolder_h
#define TicketHolder_h
#include <string>
#include <iostream>
using namespace std;
class TicketHolder {
public:
TicketHolder();
TicketHolder( std::string seat, double cost );
std::string getSeat() const;
double getCost() const;
friend std::ostream& operator<< (std::ostream& os, const TicketHolder & t);
private:
std::string my_Seat;
double my_Cost;
};
#endif
TicketHolder.cpp
#include "TicketHolder.h"
TicketHolder::TicketHolder(){
}
TicketHolder::TicketHolder( std::string seat, double cost ){
my_Seat = seat;
my_Cost = cost;
}
std::string TicketHolder::getSeat() const{
return (my_Seat);
}
double TicketHolder::getCost() const{
return (my_Cost);
}
std::ostream& operator<< (std::ostream& os, const TicketHolder & t){
return os;
}
RockConcert.h
#ifndef RockConcert_h
#define RockConcert_h
#include <string>
#include <iostream>
#include <stdexcept>
#include "TicketHolder.h"
#include "SeatAlreadySold.h"
#include "SeatNotFound.h"
class RockConcert {
public:
public:
RockConcert( std::string date, std::string location );
void sellTicket( std::string seat, double cost ) throw (SeatAlreadySold);
TicketHolder getTicket( std::string seat ) throw (SeatNotFound);
double getProceeds( );
friend std::ostream& operator<< ( std::ostream& out, const RockConcert & r );
private:
TicketHolder myTickets[ 20 ];
int myNumberOfTicketsSeenSoFar;
std::string my_When;
std::string my_Where;
};
#endif
RockConcert.cpp
#include "RockConcert.h"
#include "TicketHolder.h"
RockConcert::RockConcert( std::string date, std::string location ) {
my_When = date;
my_Where = location;
}
void RockConcert::sellTicket( std::string seat, double cost ) throw (SeatAlreadySold){
}
TicketHolder RockConcert::getTicket( std::string seat ) throw(SeatNotFound) {
}
double RockConcert::getProceeds( ){
return (myNumberOfTicketsSeenSoFar);
}
std::ostream& operator<< ( std::ostream& out, const RockConcert & r ){
return out;
}
驱动程序
// driver
// function main
#include "TicketHolder.h"
#include "RockConcert.h"
#include <iostream>
#include <stdexcept>
int main(int argc, const char * argv[])
{
RockConcert megaDeath( "Sept 1", "Staples Center" );
megaDeath.sellTicket( "Row Q Seat 20", 120.00 );
megaDeath.sellTicket( "Row Q Seat 21", 120.00 );
megaDeath.sellTicket( "Row SSS Seat 12", 50.00 );
TicketHolder ticket = megaDeath.getTicket( "Row Q Seat 21" );
// Print out the concert and its tickets
std::cout << megaDeath << std::endl;
try {
megaDeath.sellTicket( "Row T Seat 30", 65.00 );
} catch( SeatAlreadySold sas ) {
std::cout << "An error occurred here for the reason:";
std::cout << sas.what(std::endl:endl;
}
// Print out the library and its book - notice the difference
std::cout << megaDeath << std::endl;
// Let's try to throw some errors...
try {
// can't sell a ticket that has already been sold
megaDeath.sellTicket( "Row Q Seat 21", 120.00 );
std::cout << "An error occurred here..." ;
} catch( SeatAlreadySold sas ) {
sas.what();
}
try {
// can't get a ticket that has not been sold
megaDeath.getTicket( "Row A Seat 1" );
std::cout << "An error occurred here..." ;
} catch( SeatNotFound snf ) {
snf.what();
}
}
最佳答案
我不确定这到底是什么问题，但是我倾向于创建一个映射票证ID的std::map（只要您是一致）到TicketHolder实例。您的TicketHolder类（我认为最好将其命名为Ticket）应包含一个布尔型“ sold”属性。
在您的getTicket()方法中，在std::map中进行简单的查找就可以了，而且非常快速。
您的sellTicket()方法应首先调用getTicket()，然后检查返回的票证的“已售出”属性（如果已售出则抛出异常）。如果不是，则设置TicketHolder::sold = true。您还应该将票据成本添加到到目前为止的收益总额中。
其他可能有用的一般规则：
您可以在构造函数中使用初始化列表
避免在C ++中使用异常说明符，否则它们可能无法满足您的要求
除非您真的知道自己在做什么，否则请务必按值抛出异常，并按const引用进行捕获。
避免在函数参数中复制std::string和其他复杂对象
同样，请仔细考虑您的方法返回类型何时应为副本，何时应为引用，何时应为const引用以及何时应为（智能）指针。