LNK 2019 / 1120 Errors with my header / source file practice with Double Linked Lists

Question

Could you help me figure out why I'm getting these 2019 Errors? I'm pretty sure all the files are saved in the correct places, and I think I'm using the correct conventions for header files? This is a lab for my systems programming class.

Here are the errors:

1>main.obj : error LNK2019: unresolved external symbol "public: __thiscall DLL::intDLL::intDLL(void)" (??0intDLL@DLL@@QAE@XZ) referenced in function _main

1>main.obj : error LNK2019: unresolved external symbol "public: __thiscall DLL::intDLL::~intDLL(void)" (??1intDLL@DLL@@QAE@XZ) referenced in function _main

1>main.obj : error LNK2019: unresolved external symbol "public: void __thiscall DLL::intDLL::addFront(int)" (?addFront@intDLL@DLL@@QAEXH@Z) referenced in function _main

1>main.obj : error LNK2019: unresolved external symbol "public: int __thiscall DLL::intDLL::getFront(void)" (?getFront@intDLL@DLL@@QAEHXZ) referenced in function _main

1>c:\users\josh\documents\visual studio 2012\Projects\Lab10\Debug\Lab10.exe : fatal error LNK1120: 4 unresolved externals

intDLL.h file:

#include <iostream>
using std::cout;
using std::endl;

class intDLL {

public:
    intDLL();
    intDLL(const intDLL &original);
    ~intDLL();
    void addFront(int inValue);
    void addBack(int inValue);
    void setBack();
    int getFront();
    int getBack();

    struct node {
        int value;
        node *next;
        node *prev;
    };

private:
    node *front;
    node *back;

};

intDLL.cpp

#include <iostream>
#include "intDLL.h"
using std::cout;
using std::endl;


intDLL::intDLL() {
    front = 0;
    back = 0;
}

void intDLL::setBack() {
    node *tempNode = new node;
    if(front == 0) {
        return;
    }

    tempNode = front;
    while(tempNode->back != 0) {
        tempNode = tempNode->prev;  
    }

    back = tempNode;
}

void intDLL::addFront(int inValue) {
    if(front == 0) {
        node *newFront = new node;
        newFront->value = inValue;
        newFront->next = 0;
        newFront->prev = 0;
    }
    else {
        node *newFront = new node;
        newFront->value = inValue;
        newFront->prev = front;
        front->next = newFront;
        newFront->next = 0;
        front = newFront;
    }

    setBack();
}

void intDLL::addBack(int inValue) {
    setBack();
    node *newBack = new node;
    newBack -> value = inValue;
    back->prev = newBack;
    newBack->next = back;
    back = newBack;
}

int intDLL::getFront() {
    return front->value;
}

int intDLL::getBack() {
    return back->value;
}

main:

#include <iostream>
#include "intDLL.h"
using std::cout;
using std::endl;

int main(int argc, char* argv[]) {
    intDLL test = intDLL();
    test.addFront(3);
    test.addFront(4);
    test.addFront(5);
    std::cout << test.getFront() << endl;

    return 0;
}

Please show the complete error messages. The only hint, I get from `LNK2019`, is it must be linker related. — Olaf Dietsche, Feb 13 '13 at 00:27
Added the error messages. Why the downvote on my very first post? :( — josh, Feb 13 '13 at 00:31
Because just outputting raw code and saying "i have an error message" isn't good. Removed downvote. But still you should add details like how you compile it — CharlesB, Feb 13 '13 at 00:35

score 0 · Answer 1 · edited May 23 '17 at 10:32

0

Not sure what's the real error message, but seems like you haven't implemented a few functions, for sample

intDLL(const intDLL &original);
~intDLL();

Check your function definitions to make sure every functions declared are defined. Also make sure all cpp files are compiled and linked.

Another error is intDLL::node has no back member

void intDLL::setBack() {
    intDLL::node *tempNode = new node;
     ^^^^ node is defined in intDLL, you need provide scope
    if(front == 0) {
       return;
    }

  tempNode = front;
  while(tempNode->back != 0) {
                  ^^^ intDLL::node has no back member
    tempNode = tempNode->prev;  
   }

  back = tempNode;
}

See this SO link.

edited May 23 '17 at 10:32

Community

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1

answered Feb 13 '13 at 00:31

billz

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I commented out those unused functions that were declared in the header file (Hadn't gotten to writing them yet because of these errors), and got them same last 3 error messages. I assumed that when I do "start without debugging" in Visual Studio 2012 it compiled all the files in the project and did appropriate linking. Not the case? – josh Feb 13 '13 at 00:41

LNK 2019 / 1120 Errors with my header / source file practice with Double Linked Lists

1 Answers1