参考文献 C++另一个文件中的结构对象？
我正在尝试使正在进行的游戏更加模块化。我希望能够声明游戏中所有 room_t 对象的单个数组 (room_t rooms[])，将其存储在 world.cpp 中并从其他文件调用它。
下面的截断代码不起作用，但据我所知。我想我需要使用 extern 但一直无法找到正确工作的方法。如果我尝试在头文件中声明数组，则会收到重复对象错误（我假设每个文件都调用 world.h）。
main.cpp
#include <iostream>
#include "world.h"
int main()
{
int currentLocation = 0;
cout << "Room: " << rooms[currentLocation].name << "\n";
// error: 'rooms' was not declared in this scope
cout << rooms[currentLocation].desc << "\n";
return 0;
}
world.h
#ifndef WORLD_H
#define WORLD_H
#include <string>
const int ROOM_EXIT_LIST = 10;
const int ROOM_INVENTORY_SIZE = 10;
struct room_t
{
std::string name;
std::string desc;
int exits[ROOM_EXIT_LIST];
int inventory[ROOM_INVENTORY_SIZE];
};
#endif
world.cpp
#include "world.h"
room_t rooms[] = {
{"Bedroom", "There is a bed in here.", {-1,1,2,-1} },
{"Kitchen", "Knives! Knives everywhere!", {0,-1,3,-1} },
{"Hallway North", "A long corridor.",{-1,-1,-1,0} },
{"Hallway South", "A long corridor.",{-1,-1,-1,1} }
};
I'm in the process of trying to make a game-in-progress more modular. I'd like to be able to declare a single array of all the room_t objects in the game (room_t rooms[]), store it in world.cpp and call it from other files.
The truncated code below does not work, but it's as far as I've gotten. I think I need to use extern but have not been able to find a method that works correctly. If I try and declare the array in the header file, I get a duplicate object error (as each file calls world.h, I'd assume).
main.cpp
#include <iostream>
#include "world.h"
int main()
{
int currentLocation = 0;
cout << "Room: " << rooms[currentLocation].name << "\n";
// error: 'rooms' was not declared in this scope
cout << rooms[currentLocation].desc << "\n";
return 0;
}
world.h
#ifndef WORLD_H
#define WORLD_H
#include <string>
const int ROOM_EXIT_LIST = 10;
const int ROOM_INVENTORY_SIZE = 10;
struct room_t
{
std::string name;
std::string desc;
int exits[ROOM_EXIT_LIST];
int inventory[ROOM_INVENTORY_SIZE];
};
#endif
world.cpp
#include "world.h"
room_t rooms[] = {
{"Bedroom", "There is a bed in here.", {-1,1,2,-1} },
{"Kitchen", "Knives! Knives everywhere!", {0,-1,3,-1} },
{"Hallway North", "A long corridor.",{-1,-1,-1,0} },
{"Hallway South", "A long corridor.",{-1,-1,-1,1} }
};
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评论（3）
只需在
world.h文件中添加extern room_t rooms[];即可。Just add
extern room_t rooms[];in yourworld.hfile.世界.h
world.h
问题是您试图引用在 .cpp 文件中声明的变量。在该文件的范围之外没有对此进行处理。为了解决这个问题，为什么不在 .h 文件中声明变量但有一个 Init 函数：
然后在 .cpp 中
The problem is that you're trying to reference a variable you've declared in the .cpp file. There's no handle on this outside of the scope of this file. In order to fix this, why not declare the variable in the .h file but have an Init function:
Then in the .cpp