c++ - 如何在不使用全局变量的情况下在函数之间使用多个变量？

Question

利用我在编程课上学到的知识，我正在用 C++ 制作一个基于文本的小型回合制战斗游戏。请记住，我可能不知道如何使用或了解更复杂的概念。

我在游戏中有很多变量，用于检查玩家是否拥有某些元素的 bool 值，用于健康值，护甲等的整数。我知道我不应该使用全局变量，所以我打算使用指针来传递函数之间的变量。

通常这不是问题:

attack(int *health, int *armor);

但我有类似的东西:

attack(int *health, int *armor, int *enemyHealth, int *enemyArmor, ......etc);

输入变得越来越乏味，使用全局变量将是一个即时的解决方案。但我想知道另一种方式。此外，有时在调用函数时我不需要传递“*armor”，例如如果玩家没有穿任何盔甲。这也意味着我需要创建很多这样的东西:

if (*armor != nullptr)
{
    do things
}

解决方案？如果不清楚，请提前道歉。我是这个网站的新手，我可能需要一段时间才能理解您的回答。谢谢大家!! :)

Here是完整的代码(这个问题的实例还不多，因为我刚刚遇到它，但查看我的函数调用会使其更加清晰)

Answer 1

避免传递数百个变量的方法是使用类或结构组织数据。这个想法是您将所有相关变量收集到一个模拟游戏某些部分的“用户定义类型”中。

例如，我编写了一个非常小的冒险游戏供您检查，看看它是如何工作的:

Wendy 和 Bob 的冒险

#include <string>
#include <iostream>

// this just declares the makeup
// of weapons, it doesn't create any
struct weapon
{
    std::string name;
    int damage;
};

// this just declares the makeup
// of players, it doesn't create any
// NOTE: it contains a weapon
struct player
{
    bool alive;
    std::string name;
    bool male;
    int health;
    int armor;
    weapon weap;
};

// This performs a single attack
void attack(player& a, player& b)
{
    std::cout << "\n";
    std::cout << a.name;
    std::cout << " strikes at ";
    std::cout << b.name;
    std::cout << " with " << (a.male?"his":"her") << " ";
    std::cout << a.weap.name;

    int damage = std::rand() % a.weap.damage;

    if(damage == 0)
    {
        std::cout << " and " << (a.male?"he":"she") << " misses.";
        return;
    }

    int wound = damage - b.armor;

    if(wound <= 0)
    {
        std::cout << " causing no harm.";
        return;
    }

    std::cout << " inflicting ";
    std::cout << wound;
    std::cout << " damage";

    b.health -= wound;

    if(b.health < 0)
    {
        b.alive = false;
        std::cout << " killing " << (b.male?"him":"her") << " dead!";
    }
    else if(b.health < 10)
    {
        std::cout << " causing " << (b.male?"him":"her") << " to stumble!";
    }
    else if(b.health < 20)
    {
        std::cout << " causing " << (b.male?"him":"her") << " to stagger!";
    }
    else if(b.health < 30)
    {
        std::cout << " irritating " << (b.male?"him":"her") << " somewhat.";
    }
}

int main()
{
    std::srand(std::time(0));

    std::cout << "Welcome to the Adventures of Wendy & Bob\n";

    // We actually create a player here
    player bob;

    // Give it relevant data
    bob.alive = true;
    bob.name = "Bob";
    bob.male = true;
    bob.armor = 4;
    bob.health = 100;
    bob.weap.name = "knife";
    bob.weap.damage = 16;

    // same with another player
    player wendy;

    wendy.alive = true;
    wendy.name = "Wendy";
    wendy.male = false;
    wendy.armor = 3;
    wendy.health = 100;
    wendy.weap.name = "blade";
    wendy.weap.damage = 20;

    // Keep fighting till someone dies!
    while(bob.alive && wendy.alive)
    {
        attack(bob, wendy);

        if(wendy.alive && bob.alive)
            attack(wendy, bob);
    }

}