Unresolved external issue when compiling multi-source files - c++

Question

I have a project that consists of 2 CPP files (main.cpp and Car.cpp) and a header file (Car.h). The program is meant to allow a user to enter the model, make, and speed of a car and displays the modified speed. My issue is that when I compile the project, I receive a "1 unresolved externals" issue like so:
1>main.obj : error LNK2019: unresolved external symbol "public: __thiscall Car::Car(void)" (??0Car##QAE#XZ) referenced in function _main
1>C:\Users\Shaidi\Desktop\Classes\CIST 2362\Projects\main\Debug\main.exe : fatal error LNK1120: 1 unresolved externals
Here is the main.cpp file:
// main.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "Car.h"
#include <iostream>
#include <string>
using namespace std;
int main()
{
string make;
int model, speed;
Car c;
//user input and assignment for make, model, and speed
cout << "Enter the make of the car: " <<endl;
cin >> make;
c.setMake(make);
cout << "Enter the model of the car: " <<endl;
cin >> model;
c.setYearModel(model);
cout << "Enter the speed of the car: " <<endl;
cin >> speed;
c.setSpeed(speed);
//print make and model
cout << "Car make: " << c.getMake() <<endl;
cout << "Car model: " << c.getYearModel() << endl;
cout << "Car speed: " << c.getSpeed() <<endl;
//loops to calculate and print acceleration and braking
for (int i = 0; i < 5; i ++){
cout << "Car speed after acceleration: " <<c.accelerate() <<endl;
}
for (int i = 0; i < 5; i ++){
cout << "Car speed after braking: " <<c.brake() <<endl;
}
return 0;
} //end main
Here is the Car.cpp file:
// Car.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "Car.h"
#include <cstdlib>
#include <string>
#include <iostream>
using namespace std;
Car::Car(int y, string m)
{
string make = m;
int year = y;
speed = 0;
}
void Car::setYearModel(int y)
{
yearModel = y;
}
void Car::setSpeed(int s)
{
if (s >= 0){
speed = s;
} else {
cout << "Invalid speed";
exit(EXIT_FAILURE);
}
}
void Car::setMake(string m)
{
make = m;
}
int Car::getYearModel()
{
return yearModel;
}
int Car::getSpeed()
{
return speed;
}
string Car::getMake()
{
return make;
}
int Car::accelerate()
{
return speed + 5;
}
int Car::brake()
{
return speed - 5;
}
And here is the Car.h file:
#ifndef CAR_H
#define CAR_H
#include <string>
using namespace std;
class Car
{
private:
std::string make;
int yearModel;
int speed;
public:
Car();
Car(int, std::string);
void setYearModel(int);
void setSpeed(int);
void setMake(std::string);
int getYearModel() ;
int getSpeed() ;
int accelerate() ;
int brake() ;
std::string getMake() ;
};
#endif // CAR_H

Answer 1

You miss the implementation of default constructor of Car().
class Car
{
public:
// There is no implementation.
Car();
}

Answer 2

You've declared Car::Car() but never defined it. Either add a definition to the .cpp file, or remove the declaration from the header.
For example:
Car::Car()
{
}

Answer 3

It looks like you have defined the default constructor for car but have not implemented it. Then you declared a variable of type car which would require it to be implemented. Adding the code that Kerrek has above to the .cpp file should do the trick :)