Question

I am getting this error:

fatal error LNK1169: one or more multiply defined symbols found

Below are two files containing the code. In file 1, I have the main() function and I am calling the functions which are written in the second file named linklist.cpp.
Thanks for helping in advance.

File 1 – main.cpp

#include "stdafx.h"
# include "linklist.cpp"


int main(int argc, _TCHAR* argv[])
{
    node *link_list2;
    link_list2 = createList(31);
    addFront(link_list2,33);
    printList(link_list2);
    printf("Hello There Omer Obaid khan\n");
    return 0;
}

File 2 – linklist.cpp

# include "stdafx.h"
# include <stdlib.h>
struct node{
    node * next;
    int nodeValue;

};

node* initNode(int number);
node* createList (int value);
void addFront (node *head, int num );
void deleteFront(node*num);
void destroyList(node *list);
int getValue(node *list);

node*createList (int value)  /*Creates a Linked-List*/
{
    node *dummy_node = (node*) malloc(sizeof (node));
    dummy_node->next=NULL;
    dummy_node->nodeValue = value;
    return dummy_node;
}


void addFront (node *head, int num ) /*Adds node to the front of Linked-List*/
{
    node*newNode = initNode(num);   
    newNode->next = NULL;
    head->next=newNode;
    newNode->nodeValue=num;
}

void deleteFront(node*num)   /*Deletes the value of the node from the front*/
{
    node*temp1=num->next;

    if (temp1== NULL) 
    {
        printf("List is EMPTY!!!!");
    }
    else
    {
        num->next=temp1->next;
        free(temp1);
    }

}

void destroyList(node *list)    /*Frees the linked list*/
{
    node*temp;
    while (list->next!= NULL) 
    {
        temp=list;
        list=temp->next;
        free(temp);
    }
    free(list);
}

int getValue(node *list)    /*Returns the value of the list*/
{
    return((list->next)->nodeValue);
}


void printList(node *list)   /*Prints the Linked-List*/
{

    node*currentPosition;
    for (currentPosition=list->next; currentPosition->next!=NULL; currentPosition=currentPosition->next)  
    {
        printf("%d \n",currentPosition->nodeValue);
    }   
    printf("%d \n",currentPosition->nodeValue);

}

node*initNode(int number) /*Creates a node*/
{
    node*newNode=(node*) malloc(sizeof (node));
    newNode->nodeValue=number;
    newNode->next=NULL;
    return(newNode);
}

Answer 1

I stopped reading after # include "linklist.cpp". Don’t include implementation files in other implementation files. (unless you’re doing bulk-builds, which I doubt). Separate declarations in headers and include those, and keep the definitions in the implementation files.