关于具有多个类和标头的运输程序中的继承、隐私和对象的 C++ 问题
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【中文标题】关于具有多个类和标头的运输程序中的继承、隐私和对象的 C++ 问题【英文标题】：C++ questions on Inheritance, privacy, and objects in a shipping program with multiple classes and headers 【发布时间】：2016-11-04 19:43:44 【问题描述】：我的程序应该打印来自 EndPoint toString 方法的“to”和“from”地址，但我不太清楚如何实现它。这是我的代码。如何获取 Package::Package 构造函数中的 toString 方法来打印 EndPoint 的 toString 方法的内容？
// ShippingProgram.cpp :
//
#include "stdafx.h"
#include <iomanip>
#include <stdexcept>
#include <sstream>
#include <iostream>
#include "Package.h" // Package class definition
using namespace std;
// constructor
EndPoint::EndPoint(const string& nameInfo, const string& addressInfo, const string& cityInfo, const string& stateInfo, int zipInfo)
name = nameInfo;
address = addressInfo;
city = cityInfo;
state = stateInfo;
zip = zipInfo;
string EndPoint::toString() const
ostringstream output;
output << fixed << setprecision(2); // two digits of precision
output << name << "\n" << address << "\n" <<
city << ", " << state << " " << zip;
return output.str();
Package::Package(EndPoint senderInfo, EndPoint receiverInfo, double weightInfo, double costPerOzInfo)
weight = weightInfo; // should validate
costPerOz = costPerOzInfo;
void Package::calculateCost(double)
double Package::calculateCost() const
return weight * costPerOz;
string Package::toString() const
ostringstream output;
output << fixed << setprecision(2); // two digits of precision
output << "\nFrom:\n" << senderInfo.toString() << "\n\nTo:\n" << receiver <<
"\n\nWeight: " << weight << endl <<
"\nShipping cost:\n" << calculateCost();
return output.str();
主要方法：
#include <iostream>
#include <iomanip>
#include "stdafx.h"
//#include "TwoDayPackage.h"
//#include "OvernightPackage.h"
#include "Package.h"
using namespace std;
int main()
// Three address records.
EndPoint homer "Homer Simpson", "742 Evergreen Terrace", "Springfield",
"FL", 32401 ;
EndPoint donald "Donald Duck", "1313 Webfoot Walk", "Duckburg",
"CA", 95501;
EndPoint kermit "Kermit Frog", "On the Swamp", "Leland", "MS", 38756 ;
// This calls the base class constructor (regular fee).
Package regular homer, donald, 25.0, 0.20 ;
// Defines output precision for floating point numbers (iomanip).
// cout << fixed << setprecision(2);
// Prints package parameters.
cout << "Regular package processed." << endl;
cout << regular.toString();
cout << "Shipping Cost: $" << regular.calculateCost() << endl << endl;
cout << homer.toString();
// First derived class (two-day fee added).
/* TwoDayPackage twoday donald, kermit, 17.5, 0.20, 2.0 ;
cout << "Two-day package processed." << endl;
cout << twoday.toString();
cout << "Shipping Cost: $" << twoday.calculateCost() << endl << endl;
// Second derived class (overnight fee added).
OvernightPackage overnight kermit, homer, 14.2, 0.20, 0.50 ;
cout << "Overnight package processed." << endl;
cout << overnight.toString();
cout << "Shipping Cost: $" << overnight.calculateCost() << endl << endl;
*/
这个项目要求我创建一个带有继承的运输程序。它必须包括一个私有的“EndPoint”类，它包含发送者和接收者信息，以及一个编译所有内容并将其放入字符串的“Package”类。
我的错误在于我如何让我的 Package 构造函数能够包含来自我的 EndPoint 类的信息。由于 main 方法在 Package 类必须位于的位置（EndPoint、EndPoint、Weight、Cost）进行了格式化，但它不会像那样编译。我想我只是不明白如何将 EndPoint 信息发送到 Package 对象。
这是我的错误：
-
没有构造函数实例
"Package::Package" matches the argument list argument types are: (EndPoint, EndPoint, double, double)
Error C2440 'initializing': cannot convert from 'initializer list' to 'Package'
Error C3861 'setprecision': identifier not found
包.h
#pragma once
#ifndef PACKAGE_H
#define PACKAGE_H
#include <string>
#include <iostream>
using namespace std;
class EndPoint
public:
EndPoint(const std::string&, const std::string&, const std::string&, const std::string&, int = 0.0);
void setName(const std::string&);
std::string getName() const;
void setAddress(const std::string&);
std::string getAddresss() const;
void setCity(const std::string&);
std::string getCity() const;
void setState(const std::string&);
std::string getState() const;
void setZip(int);
int getZip() const;
string toString() const;
protected:
std::string name;
std::string address;
std::string city;
std::string state;
int zip;
;
class Package
public:
string toString() const;
Package(const std::string&, const std::string&, double = 0.0, double = 0.0);
void setSender(const std::string&);
std::string getSender() const;
void setReceiver(const std::string&);
std::string getReceiver() const;
void setWeight(double);
double getWeight() const;
void setCostPerOz(double);
double getCostPerOz() const;
void calculateCost(double);
double calculateCost() const;
double calculateCost(double weight, double costPerOz)
double shipping;
shipping = weight * costPerOz;
cout << "The Base Cost = " << shipping << endl << endl;
return shipping;
protected:
std::string sender;
std::string receiver;
double weight; // gross weekly sales
double costPerOz; // commission percentage
;
#endif
包.cpp
#include "stdafx.h"
#include <iomanip>
#include <stdexcept>
#include <sstream>
#include "Package.h" // Package class definition
using namespace std;
// constructor
EndPoint::EndPoint(const string& nameInfo, const string& addressInfo, const string& cityInfo, const string& stateInfo, int zipInfo)
name = nameInfo;
address = addressInfo;
city = cityInfo;
state = stateInfo;
zip = zipInfo;
void EndPoint::setName(const string& nameInfo)
name = nameInfo;
string EndPoint::getName() const return name;
void EndPoint::setAddress(const string& addressInfo)
address = addressInfo;
string EndPoint::getAddresss() const return address;
void EndPoint::setCity(const string& cityInfo)
city = cityInfo;
string EndPoint::getCity() const return city;
void EndPoint::setState(const string& stateInfo)
state = stateInfo;
string EndPoint::getState() const return state;
void EndPoint::setZip(int zipInfo)
zip = zipInfo;
int EndPoint::getZip() const
return zip;
string EndPoint::toString() const
ostringstream output;
output << fixed << setprecision(2); // two digits of precision
output << name << "\n" << address << "\n" <<
city << ", " << state << " " << zip;
return output.str();
string EndPoint::getState() const return state;
Package::Package(const string& senderInfo, const string& receiverInfo, double weightInfo, double costPerOzInfo)
sender = senderInfo; // should validate
receiver = receiverInfo; // should validate
weight = weightInfo; // should validate
costPerOz = costPerOzInfo;
void Package::setSender(const string& senderInfo)
sender = senderInfo; // should validate
string Package::getSender() const return sender;
void Package::setReceiver(const string& receiverInfo)
receiver = receiverInfo; // should validate
string Package::getReceiver() const return receiver;
void Package::setWeight(double weightInfo)
if (weightInfo < 0.0)
throw invalid_argument("The package weight must be >= 0.0");
weight = weightInfo;
double Package::getWeight() const return weight;
void Package::setCostPerOz(double costPerOzInfo)
costPerOz = costPerOzInfo;
double Package::getCostPerOz() const
return costPerOz;
double Package::calculateCost() const
return weight * costPerOz;
string Package::toString() const
ostringstream output;
output << fixed << setprecision(2); // two digits of precision
output << "From:\n" << sender << "\n\nTo:\n" << receiver <<
"\n\nWeight: " << weight << endl <<
"\nShipping cost: " << calculateCost();
return output.str();
Main.cpp
#include <iostream>
#include <iomanip>
#include "stdafx.h"
//#include "TwoDayPackage.h"
//#include "OvernightPackage.h"
#include "Package.h"
using namespace std;
int main()
// Three address records.
EndPoint homer "Homer Simpson", "742 Evergreen Terrace", "Springfield",
"FL", 32401 ;
EndPoint donald "Donald Duck", "1313 Webfoot Walk", "Duckburg",
"CA", 95501;
EndPoint kermit "Kermit Frog", "On the Swamp", "Leland", "MS", 38756 ;
// This calls the base class constructor (regular fee).
Package regular homer, donald, 25.0, 0.20 ;
// Defines output precision for floating point numbers (iomanip).
cout << fixed << setprecision(2);
// Prints package parameters.
cout << "Regular package processed." << endl;
cout << regular.toString();
cout << "Shipping Cost: $" << regular.calculateCost() << endl << endl;
// First derived class (two-day fee added).
/* TwoDayPackage twoday donald, kermit, 17.5, 0.20, 2.0 ;
cout << "Two-day package processed." << endl;
cout << twoday.toString();
cout << "Shipping Cost: $" << twoday.calculateCost() << endl << endl;
// Second derived class (overnight fee added).
OvernightPackage overnight kermit, homer, 14.2, 0.20, 0.50 ;
cout << "Overnight package processed." << endl;
cout << overnight.toString();
cout << "Shipping Cost: $" << overnight.calculateCost() << endl << endl;
*/
我已经注释掉了这里的代码块，因为我试图让第一部分工作，然后再深入研究其余部分。
编辑：
谢谢大家的建议！我进行了一些编辑并删除了大量额外的代码（getter 和 setter。我用 java 学习了...），并且我已经让程序按预期编译和工作，除了一个小但重要的问题。
【问题讨论】：
请edit您的问题提供minimal reproducible example。 顺便说一句，你不需要使用预编译头文件或stdafx.h。对于较小的项目，构建时间并没有减少，尤其是在开发阶段。
我建议将EndPoint 放入单独的头文件和源文件中。
最简单的解决方法：#include <iomanip> 应该照顾 setprecision。
我已经编辑了我的代码并实施了你们的一些建议，但遇到了一个有趣的问题，我已经编辑了我的原始问题以包含在内。谢谢！
【参考方案1】：
没有构造函数“Package::Package”的实例与参数匹配 列表参数类型为：(EndPoint, EndPoint, double, double)
在您的代码中：Package regular homer, donald, 25.0, 0.20 ; 您将错误的变量传递给构造函数的参数，这是第一个和第二个参数的 Endpoint 对象
你拥有的是：
Package(const std::string&, const std::string&, double = 0.0, double = 0.0);
它接受一个 std::string 对象作为第一个和第二个参数。
无法从“初始化列表”转换为“包”
解决问题 1 将解决此问题
我不知道为什么你会得到第三个，因为你的 main 中有 iomanip
【讨论】：
在该项目的说明中，它说将端点设置为私有（我没有这样做，因为它破坏了一切）。我只是不明白。如果我更改所有内容以使用端点，我会得到更多类型不匹配的错误，并且它说没有默认端点构造函数，但如果我创建一个繁荣另一个错误......我在这里拉头发。如何将端点传递给包构造函数？ @BrenBailey 抱歉，但我昨天睡着了，要将端点传递给构造函数，你必须让它接受参数的端点，就像你在字符串中所做的那样，或者像这个 Package(const EndPoint& ep ,const EndPoint& ,double,double) ，顺便重载一下。以上是关于关于具有多个类和标头的运输程序中的继承、隐私和对象的 C++ 问题的主要内容，如果未能解决你的问题，请参考以下文章