创建单独的实现文件和头文件

从当前源文件开始，进行增量更改。

首先，将class Player的定义移动到名为player.h的文件中；那是一个头文件。然后将Player的成员函数的定义移动到名为player.cpp的文件中；那是一个实现文件。

现在您当前的文件不会编译，因为它不知道class Player。所以添加`#include"player.h"。

现在对class Lobby执行相同的操作。

现在，原始源文件中只剩下int main()和一些#include指令。这是你的驱动程序文件。

以下是您的文件，分为头文件和实现文件。遵循这里定义之前声明的简单原则。头文件的Included#pragma once作为include guard，在任何情况下，这些头文件都会多次包含到源文件中。我不建议在头文件中使用using namespace std，请尝试将它们移到源文件中，并在头文件(如std::string(中使用命名空间限定名称。

player.h

#pragma once
#include <iostream>
#include <string>
using namespace std;
class Player
{
public:  
Player(const string& name = "");
string GetName() const;
Player* GetNext() const;
void SetNext(Player* next);
private:
string m_Name;
Player* m_pNext;  //Pointer to next player in list
};

播放器Imp.cpp

#include "player.h"
Player::Player(const string& name): 
m_Name(name), 
m_pNext(0) 
{}
string Player::GetName() const
{
return m_Name;
}
Player* Player::GetNext() const
{
return m_pNext;
}
void Player::SetNext(Player* next)
{
m_pNext = next;
}

大厅.h

#pragma once
#include <iostream>
#include <string>
using namespace std;
class Player;
class Lobby
{
friend ostream& operator<<(ostream& os, const Lobby& aLobby);
public:
Lobby();
~Lobby();
void AddPlayer();
void RemovePlayer();
void Clear();
private:
Player* m_pHead;  
};

lobbyImp.cpp

#include "lobby.h"
#include "player.h"
Lobby::Lobby():
m_pHead(0)
{}
Lobby::~Lobby()
{
Clear();
}
void Lobby::AddPlayer()
{
//create a new player node
cout << "Please enter the name of the new player: ";
string name;
cin >> name;
Player* pNewPlayer = new Player(name);
//if list is empty, make head of list this new player
if (m_pHead == 0)
{
m_pHead = pNewPlayer;
}
//otherwise find the end of the list and add the player there
else
{
Player* pIter = m_pHead;
while (pIter->GetNext() != 0)
{
pIter = pIter->GetNext();       
}
pIter->SetNext(pNewPlayer);
}
}
void Lobby::RemovePlayer()
{
if (m_pHead == 0)
{
cout << "The game lobby is empty.  No one to remove!n";
}
else
{
Player* pTemp = m_pHead;
m_pHead = m_pHead->GetNext();
delete pTemp;
}
}
void Lobby::Clear()
{
while (m_pHead != 0)
{
RemovePlayer();
}
}

播放器测试.cpp

#include "player.h"
#include "lobby.h"
ostream& operator<<(ostream& os, const Lobby& aLobby)
{
Player* pIter = aLobby.m_pHead;
os << "nHere's who's in the game lobby:n";
if (pIter == 0)
{
os << "The lobby is empty.n";
}
else
{
while (pIter != 0)
{   
os << pIter->GetName() << endl;
pIter = pIter->GetNext();
}
}
return os;
}
int main()
{
Lobby myLobby;
int choice;
do
{
cout << myLobby;
cout << "nGAME LOBBYn";
cout << "0 - Exit the program.n";
cout << "1 - Add a player to the lobby.n";
cout << "2 - Remove a player from the lobby.n";
cout << "3 - Clear the lobby.n";
cout << endl << "Enter choice: ";
cin >> choice;
switch (choice)
{
case 0: cout << "Good-bye.n"; break;
case 1: myLobby.AddPlayer(); break;  
case 2: myLobby.RemovePlayer(); break;
case 3: myLobby.Clear(); break;
default: cout << "That was not a valid choice.n";
}
}
while (choice != 0);
return 0;
}

已编辑

请阅读以下文章以了解C++编译的更多信息。

https://en.wikipedia.org/wiki/Include_directive

http://faculty.cs.niu.edu/~mcmahon/CS241/Notes/compaile.html

https://www.toptal.com/c-plus-plus/c-plus-plus-understanding-compilation