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所以我正在自学 C++ 并完成了这个项目，以测试我对函数的所有知识（我知道其中一些可以使用数组更容易完成，但这不是重点）。它基本上是一个有点美化的石头剪刀布回合制战斗游戏，我已经折叠了下面不太相关的功能。

无论如何，原来的工作正常，但战斗主（）非常臃肿（包含整个战斗解决），我想尝试将其分离成它自己的函数。阻止我这样做是因为知道函数只能返回一个变量，但后来我读到了通过引用传递，这应该允许战斗解析修改由战斗主传递给它的参数的值。

但是，这似乎对我不起作用。我不知道我是否只是使用了错误的语法，但似乎只要我尝试通过引用传递，由于重载，函数原型就开始与函数定义发生冲突。有什么建议么？

代码：

#include <iostream>
using namespace std;
bool main();
int main_menu();
bool rules();
int combat_main();
int combat_hero(int,int,int,int);
int combat_nemesis(int,int,int,int);
int combat_resolve(int,int,int,int,int,int);
int combat_end(int,int);
bool main() {...}
int main_menu() {...}
bool rules() {...}
int combat_main() {
    int play_again=0;
    do {
        bool active_battle=1;
        cout << "Let the battle begin! Show no mercy!\n" << '\n';
        int round_number=0;
        int hero_health=5;
        int hero_energy=2;
        int nemesis_health=5;
        int nemesis_energy=2;
        do {
            if((hero_health<1)||(nemesis_health<1)) {
                active_battle=0;
            }
            //recognizes that battle has ended
            else {
                ++round_number;
                cout << "Round " << round_number << '\n' << '\n';
                int hero_action= combat_hero(hero_health,hero_energy,nemesis_health,nemesis_energy);
                //receives player's choice of action
                int nemesis_action= combat_nemesis(hero_health,hero_energy,nemesis_health,nemesis_energy);
                //decides AI's choice of action
                combat_resolve(hero_action,nemesis_action,hero_health,hero_energy,nemesis_health,nemesis_energy);
                //decides round outcome from hero_action and nemesis_action
                if(hero_action==0) {
                    hero_health=0;
                //automatically ends battle if player opts to concede defeat
                }
            }
        }
        while(active_battle==1);
        //cycles combat rounds until one opponent loses
        play_again=combat_end(hero_health,nemesis_health);
        //prompts player with option to play again at end of battle
    }
    while(play_again==1);
    //repeats if "play again" selected after battle ends
    return play_again;
}
int combat_hero(int hero_health,int hero_energy,int nemesis_health,int nemesis_energy)  {...}
int combat_nemesis(int hero_health,int hero_energy,int nemesis_health,int nemesis_energy)  {...}
int combat_resolve(int hero_action,int nemesis_action,int &hero_health,int &hero_energy,int &nemesis_health,int &nemesis_energy)  {...}
int combat_end(int hero_health,int nemesis_health) {...}

编译错误：

1   error LNK2001: unresolved external symbol "int __cdecl combat_resolve(int,int,int,int,int,int)" (?combat_resolve@@YAHHHHHHH@Z)
2   error LNK1120: 1 unresolved externals
3   IntelliSense: more than one instance of overloaded function "combat_resolve" matches the argument list:
            function "combat_resolve(int, int, int, int, int, int)"
            function "combat_resolve(int hero_action, int nemesis_action, int &hero_health, int &hero_energy, int &nemesis_health, int &nemesis_energy)"
            argument types are: (int, int, int, int, int, int)
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2 回答 2

2

问题是您将战斗解决定义为仅按值传递：

开始时：

int combat_main();
int combat_hero(int,int,int,int);
int combat_nemesis(int,int,int,int);
int combat_resolve(int,int,int,int,int,int); // <-- passing by value
int combat_end(int,int);

最后（假设您在此处定义）通过引用传递一些值：

int combat_hero(int hero_health,int hero_energy,int nemesis_health,int nemesis_energy)
int combat_nemesis(int hero_health,int hero_energy,int nemesis_health,int nemesis_energy) 
int combat_resolve(int hero_action,int nemesis_action,int &hero_health,int &hero_energy,int &nemesis_health,int &nemesis_energy)  // <-- passing some parameter as reference
int combat_end(int hero_health,int nemesis_health)
于 2013-09-17T20:51:07.610 回答
1

下面您复制了大部分函数原型（但没有参数名称）。

不匹配copmbat_resolve：

int combat_resolve(int hero_action,int nemesis_action,int &hero_health,int &hero_energy,int &nemesis_health,int &nemesis_energy);

对比

int combat_resolve(int,int,int,int,int,int);

请注意参考参数的缺失&。查看它在 IdeOne 上的编译：

int combat_resolve(int,int,int&,int&,int&,int&);  // FIX

另外，请参阅条目什么是未定义的引用/未解决的外部符号错误以及如何修复它？关于“未解决的外部因素”的一般指导

于 2013-09-17T20:50:19.927 回答