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C++类中的构造函数

c++

-2

Sam12 · 技术社区 · 6 年前

我有两个班,玩家和游戏。

class Game
{
        private:
            int maxPlayer;
            Player** playersArray;
        public:
            Game(int maxPlayer);
            ~Game();
}

playersarray中的每个索引都由指向类player的指针组成。以下构造函数不起作用,因为此消息一直出现:

error: invalid use of 'Player::Player' playersArray[i]->Player();
Game::Game(int maxPlayer)
{   this->maxPlayer=maxPlayer;
    this->playersArray = new Player*[maxPlayer];
    for(int i=0;i<maxPlayer;i++)
    {
        playersArray[i]->Player();
    }
}

这是班级选手:

class Player {
        private:
            char* player_name;
            int level;
            int life;
            int strength;
            Weapon player_weapon;
            int place; 
}

我的目标是将玩家名设置为空并不是在记忆中的任意位置。这就是player()应该做的。

1 回复 | 直到 6 年前

Remy Lebeau 6 年前

你没有填充 Game 正确排列。你想打电话给 Player() 构造函数,就好像它是一个常规类方法(它不是),更糟的是,您通过 未初始化 Player* 指针。

你需要使用 new 取而代之的是操作员,例如:

class Game
{
private:
    int maxPlayers;
    Player** playersArray;
public:
    Game(int aMaxPlayers);
    ~Game();
}

Game::Game(int aMaxPlayers)
{
    maxPlayers = aMaxPlayers;
    playersArray = new Player*[maxPlayers];
    for(int i = 0; i < maxPlayers; ++i)
        playersArray[i] = new Player; // <-- here
}

Game::~Game()
{
    for(int i = 0; i < maxPlayers; ++i)
        delete playersArray[i];
    delete[] playersArray;
}

更安全的选择是 std::unique_ptr 而不是原始指针:

#include <memory>

class Game
{
private:
    int maxPlayers;
    std::unique_ptr<std::unique_ptr<Player>[]> playersArray;
public:
    Game(int aMaxPlayers);
}

Game::Game(int aMaxPlayers)
{
    maxPlayers = aMaxPlayers;
    playersArray = std::make_unique<std::unique_ptr<Player>[]>(maxPlayers);
    for(int i = 0; i < maxPlayers; ++i)
        playersArray[i] = std::make_unique<Player>();
}

也就是说,没有必要使用 玩家* 当 Player 对象就足够了:

class Game
{
private:
    int maxPlayers;
    Player* playersArray;
public:
    Game(int aMaxPlayers);
    ~Game();
}

Game::Game(int aMaxPlayers)
{
    maxPlayers = aMaxPlayers;
    playersArray = new Player[maxPlayers];
}

Game::~Game()
{
    delete[] playersArray;
}

或:

#include <memory>

class Game
{
private:
    int maxPlayers;
    std::unique_ptr<Player[]> playersArray;
public:
    Game(int aMaxPlayers);
}

Game::Game(int aMaxPlayers)
{
    maxPlayers = aMaxPlayers;
    playersArray = std::make_unique<Player[]>(maxPlayers);
}

然后可以通过使用 std::vector 而是:

#include <vector>

class Game
{
private:
    std::vector<Player> playersArray;
public:
    Game(int maxPlayers);
}

Game::Game(int maxPlayers)
    : playersArray(maxPlayers)
{
}