Question

我试图为一个基于控制台的简单电子邮件服务器定义两个向量;一个用于存储收件箱消息，另一个用于存储已发送的消息。每个消息对象（向量元素）都有3个字符串属性。并且感谢Galik的建议，我的更新代码更清晰，构造器制作完成，我的getter和setter也完成了。然而，尽管取得了所有这些进展，我仍然不确定如何（以及在何处）将3个属性分配到一个消息对象中以用作向量元素。我在新代码中该怎么做？：

标题文件：

    //Message.h constructs the setup for email messages
#ifndef MESSAGE_H
#define MESSAGE_H
#include <string>
#include <vector>
//using namespace std;//should not use in header file.

//prototype functions
void viewInboxMessage();

class Message
{
private:
    std::string address;
    std::string subject;
    std::string text;
    std::vector<Message> inbox;
    std::vector<Message> sent;

public:
    Message()//default constuctor
    {
        //set all member variables to NULL at start of program:
        vector<Message> inbox(0);
        vector<Message> sent(0);
        address = "";
        subject = "";
        text = "";      
    }
    //contructor for message object
    Message(string address, string subject, string text);

    void setAddress(string addr);
    string getAddress();

    void setSubject(string subj);
    string getSubject();

    void setMessageText(string msgTxt);
    string getMessageText();    
};
#endif

.cpp函数文件（与具有main函数的文件分开）：

    //This class instantiates a message object for populating the
//vector arrays.
#include <string>
#include <iostream>
#include <iomanip>
#include <vector>
#include "Message.h"
using namespace std;

//Function Prototypes:
//Message inbox(string, string, string);
//Message sent(string, string, string);
void viewInboxMessage();

Message::Message(string address, string subject, string text)
{
    setAddress(address);
    setSubject(subject);
    setMessageText(text);
}

//START OF GETTERS AND SETTERS
void Message::setAddress(string addr)
{
    address = addr;
}
string Message::getAddress()
{
    return address;
}

void Message::setSubject(string subj)
{
    subject = subj;
}
string Message::getSubject()
{
    return subject;
}

void Message::setMessageText(string msgTxt)
{
    text = msgTxt;
}
string Message::getMessageText()
{
    return text;
}
//END OF GETTERS AND SETTERS

//Main Menu option 1 selected:
// print list of all messages to the console
void viewInbox()
{
    cout << "You have " << inbox.size << " new messages.\n";
    std::cout << "Index      Subject" << '\n';

    for (size_t i = 0; i < inbox.size(); ++i)
    {
        std::cout << i << "    : " << inbox[i].subject << '\n';
    }
}

//write a function that will display as many case break switch choices
//as there are messages in the inbox

//print selected message to console:
void viewInboxMessage(size_t index)
{
    if (index < inbox.size())//error: identifier "inbox" is not defined.
    {
        std::cout << "Message Number : " << index << '\n';
        std::cout << "sender: " << inbox[index].address << '\n';
        std::cout << "subject: " << inbox[index].subject << '\n';
        std::cout << "message: " << '\n';
        std::cout << inbox[index].text << '\n';
    }
}

//Main Menu option 3 selected:
Message newMessage(string address, string subject, string compose)
{
    cout << "Please enter recipient email address.\n";
    cin >> address;
    cout << "Please enter a subject for your message.\n";
    cin >> subject;
    cout << "Go ahead and type your message, and hit send when you're finished.\n";
    cin >> compose;
    vector<Message> viewSent(0)++;//add composed message to sent messages list after user sends it.
}

带主函数的文件：

    //This class contains the main function and the main menu.
#include <iostream>
#include <iomanip>
#include <string>

#include "Message.h"
using namespace std;

int main()
{
    //Message inbox[10];
    vector<Message> inbox;
    Message sent[10];
    string sender; 
    string subject;
    int numMessages;//number of messages in inbox
    int choice = 0;

    string verify = "Cartman2010";
    string userName;
    string address;
    string password;
    cout << "please enter your login username.\n";
    cin >> userName;
    cout << "please enter your email address.\n";
    cin >> address;
    cout << "please enter your password.\n";
    cin >> password;
    if (password != verify)
    {
        cout << "Invalid password. Please re-enter your password.\n";
        cin >> password;
    }
    else

    cout << "Hello " << userName << " Welcome to your mailbox. Please select an option:\n";

    //After easy login and greeting, the user needs to select an option form the main menu:
    cout << "1. View Your Inbox\n";
    cout << "2. View Sent Messages\n";
    cout << "3. Send A Message\n";
    cout << "4. Quit\n";

    cin >> choice;
    switch (choice)
    {
    case 1: Message viewInbox;//access messages (and number of messages) from vector inbox
        break;
    case 2: Message viewSent;//view the messages you've sent (and how many) from vector
        break;
    case 3: Message newMessage;
        break;
    case 4: exit();
    }

    return 0;
}

我应该在哪里分配3个字符串，＆＃34;地址＆＃34;，＆＃34;主题＆＃34;和＆＃34;文字＆＃34;进入Message对象的向量元素？

Answer 1

你说你的Message对象应该有3个字符串属性，但你的Message有6.你也似乎试图让整个邮件服务器适合你的Message类。我不确定你的整个标准，但也许这种结构可能会有所帮助：

struct Message
{
    std::string address; // sender/recipient
    std::string subject;
    std::string text; // actual message

    // compose message functions here
};

class EmailServer
{
private:
    std::vector<Message> inbox;
    std::vector<Message> sent;

public:

    // mail server functions here ...

    // print list of all messages to the console
    void viewInbox()
    {
        std::cout << "Index      Subject" << '\n';

        for(size_t i = 0; i < inbox.size(); ++i)
        {
            std::cout << i << "    : " << inbox[i].subject << '\n';
        }
    }

    // print a specific message to the console
    void viewInboxMessage(size_t index)
    {
        if(index < inbox.size())
        {
            std::cout << Message Number: " << index << '\n';
            std::cout << "sender: " << inbox[index].address << '\n';
            std::cout << "subject: " << inbox[index].subject << '\n';
            std::cout << "message: " << '\n';
            std::cout << inbox[index].text << '\n';
        }
    }


};

如何定义矢量，并使用C ++将对象存储在其中？

1 个答案: