未定義參考類函數

main.cpp中：未定義參考類函數

#include <iostream> 
#include "pokemonList.h" 
void pokemonLookup(); 

int main() { 
    pokemonLookup(); 
    return 0; 
} 

void pokemonLookup() { 
    pokemonList pL; 
    std::cout<<std::endl<<"What Pokemon do you want to look up? "; 
    std::string pokemonLookup; 
    std::cin>>pokemonLookup; 
    pL.displayPokemon(pokemonLookup); 
}

pokemonList.h：

#ifndef POKEMONLIST_H 
#define POKEMONLIST_H 
#include <iostream> 

class pokemonList 
{ 
    private: 
     struct pokemonTemplate { 
      std::string pokemonName; 
      std::string pokemonMoves[3]; 
      int pokemonLevel; 
      int baseATK; 
      int baseDEF; 
      int baseSPATK; 
      int baseSPDEF; 
      int baseSPEED; 
      }; 
     pokemonTemplate bulbasaur; 
     pokemonTemplate pikachu; 
    public: 
     void displayPokemon(std::string pokemon); 
    protected: 
}; 

#endif // POKEMONLIST_H

pokemonList.cpp：

#include "pokemonList.h" 
/* 
pokemonTemplate* bulbasaur() { 
    bulbasaur.pokemonName = "Bulbasaur"; 
    bulbasaur.pokemonMoves[3]; 
    bulbasaur.pokemonLevel = 5; 
    bulbasaur.baseATK = 10; 
    bulbasaur.baseDEF = 10; 
    bulbasaur.baseSPATK = 10; 
    bulbasaur.baseSPDEF = 10; 
    bulbasaur.baseSPEED = 10; 
} 

pokemonTemplate* pikachu() { 
    pikachu.pokemonName = "Pikachu"; 
    pikachu.pokemonMoves[3]; 
    pikachu.pokemonLevel = 5; 
    pikachu.baseATK = 8; 
    pikachu.baseDEF = 10; 
    pikachu.baseSPATK = 12; 
    pikachu.baseSPDEF = 6; 
    pikachu.baseSPEED = 15; 
} 
*/ 
void displayPokemon(std::string pokemon) { 
    std::cout<<std::endl<<"Looking up: " + pokemon<<std::endl; 
}

我意識到在pokemonList.cpp文件我有一堆壞代碼註釋掉了，這不是這個問題的含義。當我嘗試編譯，我在main.cpp中得到一個錯誤說：

D:/CodeBlocks/Projects/RelearningCPlusPlus/main.cpp:15: undefined reference to `pokemonList::displayPokemon(std::string)'

來源

2013-09-01 user2735889

將'void displayPokemon（std :: string pokemon）'改爲'void pokemonList：displayPokemon（std :: string pokemon）'並重試。 – WhozCraig

我可以建議你在地圖上存儲你的小精靈數據：'std :: map '這對於按名稱查找小精靈非常方便。 –

你定義的函數displayPokemon()，但它沒有被定義爲一個成員函數。將其定義爲類定義之外的成員函數，你需要提及的類名：

void pokemonList::displayPokemon(std::string pokemon) { 
    std::cout<<std::endl<<"Looking up: " + pokemon<<std::endl; 
}

來源

2013-09-01 02:35:22

Typo：'pokemonList：displayPokemon' - >'pokemonList :: displayPokemon'（'：' - >'::'） –

您需要更改此設置：

void displayPokemon(std::string pokemon) {

這樣：

void pokemonList::displayPokemon(std::string pokemon) {

來源

2013-09-01 02:35:45

它應該是

void pokemonList::displayPokemon(std::string pokemon){....

來源

2013-09-01 02:35:59

Dietmar的答案解決了這個問題。

但我想補充說的是，在這種情況下，最好通過引用來傳遞參數，而不是通過值std::string pokemon傳遞參數，從而減少開銷。所以displayPokemon功能應該是：

void pokemonList:displayPokemon(std::string &pokemon) const { 
    std::cout<<std::endl<<"Looking up: " + pokemon<<std::endl; 
};

另外，請記住更改相應的成員函數聲明。

來源

2013-09-01 02:55:30 lulyon

displayPokemon函數聲明爲pokemonList成員函數，但從未定義。

此：

void displayPokemon(std::string pokemon) { 
    std::cout<<std::endl<<"Looking up: " + pokemon<<std::endl; 
}

是一些其他函數（具有相同名稱）的定義，其是不是一個pokemonList類的成員函數。要告訴編譯器，這是你必須pokemonList::

void pokemonList::displayPokemon(std::string pokemon) { 
    std::cout<<std::endl<<"Looking up: " + pokemon<<std::endl; 
}

或者preceed其名稱的類pokemonList成員函數，你可以定義displayPokemon內pokemonList類：

class pokemonList 
{ 
    private: 
     struct pokemonTemplate { 
      std::string pokemonName; 
      std::string pokemonMoves[3]; 
      int pokemonLevel; 
      int baseATK; 
      int baseDEF; 
      int baseSPATK; 
      int baseSPDEF; 
      int baseSPEED; 
      }; 
     pokemonTemplate bulbasaur; 
     pokemonTemplate pikachu; 
    public: 
     void displayPokemon(std::string pokemon) { 
      std::cout<<std::endl<<"Looking up: " + pokemon<<std::endl; 
     } 
    protected: 
};

不同的是，在過去的case displayPokemon將是一個內聯函數。

來源

2013-09-01 08:48:49 cpp

未定義參考類函數

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