I am writing a simple Queue class (for exercise). This Project consists of a simple integer Node Class, which Queue Class utilizes, and the Queue class it self.
During build I am getting 3 different linker errors in my c++ project, listed below:
Error LNK2005 "public: __thiscall Node::Node(int)" (??0Node@@QAE@H@Z) already defined in fmQueue.obj Queue
Error LNK2005 "public: __thiscall Node::Node(void)" (??0Node@@QAE@XZ) already defined in fmQueue.obj Queue
Error LNK1169 one or more multiply defined symbols found Queue
I did look at where i am introducing my classes, however i dont understand where this isuue is coming from.
My code:
Node.h:
// Node.h
// 1-way linked node for use in simple integer Queue
#ifndef NODE_H
#define NODE_H
class Node
{
public:
Node();
Node(int);
int data;
Node *next;
};
Node::Node()
{
data = -1;
next = nullptr;
}
Node::Node(int x)
{
data = x;
next = nullptr;
}
#endif
fmQueue.h:
#ifndef _FMQUEUE_H
#define _FMQUEUE_H
#include <iostream>
#include "Node.h"
namespace fm
{
class fmQueue
{
Node *_head, *_tail;
void clearbuf();
public:
fmQueue();
~fmQueue();
void deQueue(); // uses front to access data, or remove data
void enQueue(int); // uses back to sort data, or add data
void dumQueue();
//int peek(); // get a copy of the front data without removing it
bool isEmpty();
};
}
#endif /* _FMQUEUE_H */
fmQueue.cpp:
#include "fmQueue.h"
using namespace fm;
//---------Private Methods--------
void fmQueue::clearbuf()
{
_head = _tail = nullptr;
}
//--------Public Methods----------
fmQueue::fmQueue()
{
clearbuf();
}
fmQueue::~fmQueue()
{
clearbuf();
}
bool fmQueue::isEmpty()
{
if (_head == _tail && _head == nullptr)
return false;
else
return true;
}
void fmQueue::enQueue(int data1)
{
Node *tempNode = new Node;
tempNode->next = nullptr;
tempNode->data = data1;
if (_head == nullptr)
{
_head = tempNode;
_tail = tempNode;
}
else
{
_tail->next = tempNode;
}
_tail = tempNode;
}
void fmQueue::deQueue()
{
Node *tempNode = new Node;
if (_head == nullptr)
std::printf("NOOOOP, THE QUEUE IS EMPTY");
else
{
tempNode = _head;
_head = _head->next;
std::cout << "the data dequeued is: " << tempNode->data; //add a print statment to see which node was deleted
delete tempNode;
}
}
void fmQueue::dumQueue()
{
Node *tempNode = new Node;
if (tempNode)
while (tempNode->next != nullptr)
{
std::cout << "Queue :" << tempNode->data;
tempNode = tempNode->next;
}
else
std::cout << "Nothing to show";
}
main.cpp:
#include"fmQueue.h"
int main()
{
fm::fmQueue my_queue;
my_queue.enQueue(2);
std::cout << "fiirst done" << std::endl;
my_queue.enQueue(4);
std::cout << "second done" <<std::endl;
my_queue.dumQueue();
std::cout << "show done" << std::endl;
my_queue.deQueue();
std::cout << "delete done" << std::endl;
my_queue.dumQueue();
std::cout << "show done" << std::endl;
my_queue.deQueue();
std::cout << "delete done" << std::endl;
return 0;
}