Question

初学者makefile家伙试图找出问题所在。在使我得到真正丑陋的错误

“对`Class :: Method（std :: __ cxx11 :: basic_string，std :: allocator>）的未定义引用””

也许有人可以帮助我了解这里的情况。当我将所有代码粘贴在一个大main.cpp文件中时，编译或运行代码都没有问题。但是，当我将代码分为各自的头文件和cpp文件时，我得到了所引用的丑陋错误。

Makefile

CXX = g++
CXXFLAGS = -Wall -g

main: main.o Hash.o 
    $(CXX) $(CXXFLAGS) -o main main.o

main.o: main.cpp Hash.cpp
    $(CXX) $(CXXFLAGS) -c main.cpp

Hash.o: Hash.cpp Hash.h
    $(CXX) $(CXXFLAGS) -c Hash.cpp

源代码

Main.cpp

#include "Hash.h"
#include <iostream>

int main() {

    HashTable Hash;
    std::string inputString = "Pot";
    Hash.Add2Hash(inputString);
    std::string returnVal = Hash.GetHashValue(inputString);
    std::cout << returnVal << std::endl;
}

Hash.h

#include <string>

#define HASH_SIZE 100000

typedef unsigned int uint_t;

struct HashElement_t{
    HashElement_t * Next;
    std::string Value;
    uint_t Key;
};

class HashTable {
    private:
        HashElement_t * HashArr[HASH_SIZE];
    public:
        void Add2Hash(std::string InsertionValue);
        uint_t GenerateHashIndex(char * c); 
        std::string GetHashValue(std::string KeyValue);
};

Hash.cpp

#include "Hash.h"
#include <string>

void HashTable::Add2Hash(std::string InsertionValue) {

    uint_t HashIndex = GenerateHashIndex(&InsertionValue[0]);

    HashElement_t * InsertionElement = new HashElement_t;
    HashElement_t * HashPosition =  HashArr[HashIndex];
    InsertionElement->Key = HashIndex;
    InsertionElement->Value = InsertionValue; 
    InsertionElement->Next = NULL;

    if(HashPosition != NULL) {
        while (HashPosition->Next != NULL) {
            HashPosition->Next = InsertionElement;
            HashPosition = HashPosition->Next; 
        }       
    } 

    this->HashArr[HashIndex] = InsertionElement;
}

uint_t HashTable::GenerateHashIndex(char * c) {
    uint_t val{10};
    while (*c != NULL) {
        val *= *c;
        c++;
    }
    return val % HASH_SIZE;
}

std::string HashTable::GetHashValue(std::string KeyValue) {
    uint_t HashIndex = GenerateHashIndex(&KeyValue[0]);
    return this->HashArr[HashIndex]->Value;
}

错误消息

$ make
g++ -Wall -g -c main.cpp
g++ -Wall -g -o main main.o
main.o: In function `main':
C:\Users\Name\Documents\Coding\Leet Coding/main.cpp:9: undefined reference to `HashTable::Add2Hash(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
C:\Users\Name\Documents\Coding\Leet Coding/main.cpp:10: undefined reference to `HashTable::GetHashValue(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
collect2.exe: error: ld returned 1 exit status
make: *** [Makefile:5: main] Error 1

未定义对`Class :: Method（std :: __ cxx11 :: basic_string <char，std :: char_traits <char>，std :: allocator <char>>）的引用”

0 个答案: