how come header variables are not recognized in its cpp file?

[SangHan]

I declared 3 private variables in header file.

I try to access one of the variable in its corresponding cpp file but I get an error message saying it's undefined. I did #include the header file. Why is this?

[3hM2Nwbp]

Are your accesses to the variables properly qualified? If you're not working in the same scope, without any using-declarations, then you will have to explicitly add the namespace to qualify access to the variable.

// example.hpp
namespace mynamespace
{
 class Example
 {
   int x; 
   static int y;
  public:
   Example(int x); 
 };
}

// example.cpp

int mynamespace::Example::y = 4;

mynamespace::Example::Example(int x) : x(x)
{

}

void func()
{
  int local_copy_of_y = mynamespace::Example::y;
}

[SangHan]

Thanks for your help. Unfortunately, it's greek to me what you just said. Here is my code

BELOW IS THE HEADER FILE Car.h

#pragma once
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;


class Car
{
// Public Interface

private:


// Variable Declarations
int year, speed;
std::string make;


public:
// Class Constructor(s)
Car(int year, string make)
{

year = year;
speed = 0;
make = make;


}




// Class Destructor
~Car(void);

// Client Methods

int accelerate(int speed);
int brake(int speed);

int ObtainYr();
string ObtainMake();
int ObtainSpeed();
int Accelerate();
void getDisplay();




};

====================================
Below is the Car.CPP

#include "Car.h" // Class Definition file
#include <stdio.h>
#include "stdafx.h"
#include <string.h>


// Class Default Constructor

Car::Car(int Yr, string Mk, int Spd)
{
Year = Yr;
Make = Mk;
Speed = Spd;
}

===========
problem is the visual studio won't recognize Year, Make, Speed. Why?

[3hM2Nwbp]

C++ is case sensitive. In your header file, your private members are 'year', 'make', and 'speed'...however in your implementation file, you refer to them as 'Year', 'Make', and 'Speed'.

[SangHan]

Thanks Luc Lieber. I overlooked it.