Question

我编写了一个小程序，接受用户输入并创建链接列表。我在构建时遇到一个错误，似乎与HeadPointer传递到print函数有关。错误如下：

undefined reference to `PrintList(PetData*)'|
||=== Build failed: 1 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|

如果有人能指出（不打算）我正确的方向，或者甚至明确地给我一个解决方案，我会非常感激。源代码：

#include <iomanip>
#include <string>
#include <iostream>


using namespace std;

struct PetData{
    int IdNumber;
    string PetType;
    PetData *link;
};

PetData * HeadPointer=NULL;

void InsertItem(int, string, PetData*);

void PrintList(PetData*);

int main(){
    int init_IdNumber;
    string init_PetType;
    PetData * CRP = NULL;

    char cflag = 'Y';
    while (toupper(cflag) == 'Y'){
        cout << "Please Enter an ID Number: " << endl;
        cin >> init_IdNumber;

        cout << "Please Enter a Pet Type: " << endl;
        cin >> init_PetType;

        CRP = new PetData;

        InsertItem(init_IdNumber,init_PetType,CRP);
        HeadPointer=CRP;

        cout << "Would you like to enter another? (Y/N)" << endl;
        cin >> cflag;


    };


    PrintList(HeadPointer);



    return 1;
};

void InsertItem(int init_IdNumber, string init_PetType, PetData* CRP){
    CRP->PetType = init_PetType;
    CRP->IdNumber = init_IdNumber;
    CRP->link = HeadPointer;
};

void PrintList(){
    while(HeadPointer != NULL){
        cout << HeadPointer->PetType << "\t" << HeadPointer->IdNumber << endl;
        HeadPointer = HeadPointer->link;
    }

};

在任何人提起之前，这不是家庭作业。这是我的教授建议我们独立创作以准备未来的中期任务。

谢谢！

Answer 1

函数声明和定义不匹配。

该功能的原型是 void PrintList(PetData*);，定义为void PrintList()。这就是它不匹配的原因。

有更正后的代码

void PrintList(PetData* HeadPointer){
    while(HeadPointer != NULL){
        cout << HeadPointer->PetType << "\t" << HeadPointer->IdNumber << endl;
        HeadPointer = HeadPointer->link;
    }

链接列表打印功能的未定义参考

1 个答案: