Help with Excercise

[NewCComer]

My excercise is:
Improve the Lobby class from the Game Lobby program by writing a
friend function of the Player class that allows a Player object to be sent
to cout. Next, update the function that allows a Lobby object to be sent
to cout so that it uses your new function for sending a Player object to
cout.

//Game Lobby
//Simulates a game lobby where players wait

#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
};


Player::Player(const string& name): // constructor
	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;
}

class Lobby
{
	friend ostream& operator<<(ostream& os, const Lobby& aLobby); // remember ostream& os then a comma!
public:
	Lobby();
	~Lobby();
	void AddPlayer();
	void RemovePlayer();
	void Clear();
private:
	Player* m_pHead;
};

Lobby::Lobby():
m_pHead(0)
{}

Lobby::~Lobby()
{
	Clear();
}



void Lobby::AddPlayer()
{
	// creates a new player node
	cout << "Please enter the name of your 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();
		}
	}

	ostream& operator<<(ostream& os, const Lobby& aLobby) // remember ostream& os then a comma!
	{
		Player* pIter = aLobby.m_pHead;
		os << "\nHere's whos in the game lobby:\n";
			if (pIter == 0)
			{
				os << "The game 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 LOBBY\n";
		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;
}

So far I've gotten to:

class Player
{
	friend ostream& operator<<(ostream& os, const Player& aPlayer);
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
};

But have no idea how to update it to allow a lobby object to be sent to cout maybe ostream but that's as far as I get.

[NewCComer]

Anyone??? The removeplayer function also just loops even if I copy it from the original book. Please can someone help me out?

[tipaye]

Don't misunderstand the problem.

You already have a function that allows you to send a Lobby object to cout (line 116-135)

You need to create a similar function for Player objects. You've written the prototype in line 3 of the last block.

What you need to do now is
1. Provide an implementation of friend ostream& operator<<(ostream& os, const Player& aPlayer);
2. change the Lobby function ostream& operator<<(ostream& os, const Lobby& aLobby) so it uses your new output function (in line 129)

For example, and only for example:

ostream& operator<<(ostream& os, const Player& aPlayer) 
{
	{
		os << aPlayer.m_Name;
	}

	return os;
}

And then the Lobby function would change to

	ostream& operator<<(ostream& os, const Lobby& aLobby)
	{
		Player* pIter = aLobby.m_pHead;
		os << "\nHere's whos in the game lobby:\n";
			if (pIter == 0)
			{
				os << "The game lobby is empty.\n";
			}

			else
			{
				while(pIter != 0)
				{
					os << (*pIter) << endl;
					pIter = pIter->GetNext();
				}
			}

			return os;
	}