Identifier not found - error C3861 in Visual Studio 2019 - c++

Question

I have a problem with my code. Unfortunately, when compiling I get these errors all the time. What can this be caused by and how to fix it?
error C3861: 'print': identifier not found
My code:
main.cpp
#include "pojazdy.h"
#include <iostream>
using namespace std;
int main()
{
Pojazdy** poj;
int size{ 0 }, index{ 0 };
Petla(poj, size);
print(poj, size);
wyrejestruj(poj,size,0);
print(poj, size);
wyrejestruj(poj,size);
return 0;
}
pojazdy.h
#ifndef pojazdy_h
#define pojazdy_h
#include <iostream>
#include <cstdlib>
using namespace std;
class Pojazdy
{
public:
string typ;
string marka;
string model;
string z_dod;
int ilosc;
int cena;
void dodaj();
void d_pojazd(Pojazdy**& pojazdy, int& size);
void wyrejestruj(Pojazdy**& pojazdy, int& size, int index);
void print(Pojazdy** pojazdy, int size);
void Petla(Pojazdy**& p, int& size);
//void wyswietl();
int get_ilosc() { return ilosc; }
string get_typ() { return typ; }
string get_marka() { return marka; }
string get_model() { return model; }
int get_cena() { return cena; }
void set_ilosc(int x);
};
#endif
pojazdy.cpp
#include "pojazdy.h"
#include <iostream>
using namespace std;
void Pojazdy::set_ilosc(int x) { ilosc = x; }
void Pojazdy::dodaj()
{
cout << "DODAWANIE POJAZDU..." << endl;
cout << "Podaj typ pojazdu:";
cin >> typ;
cout << "Podaj marke pojazdu: ";
cin >> marka;
cout << "Podaj model pojazdu: ";
cin >> model;
cout << "Dodaj cene pojazdu: ";
cin >> cena;
}
void Petla(Pojazdy**& p, int& size) {
char z_dod;// = 'N';
do {
d_pojazd(p, size); //odpowiada za dodawnie
p[size - 1]->dodaj();
cout << "Czy chcesz zakonczyc dodawanie? Jesli tak, wcisnij Y/N: ";
cin >> z_dod;
} while (z_dod == 'N' || z_dod == 'n');//while (p[size]->z_dod == "N" ||p[size]->z_dod == "n");
}
void print(Pojazdy** pojazdy, int size) {
std::cout << "====================================" << std::endl;
for (int i{ 0 }; i < size; i++)
std::cout << "Typ: " << pojazdy[i]->get_typ() << " Marka: " << pojazdy[i]->get_marka() << " Model: " << pojazdy[i]->get_model() << " Cena: " << pojazdy[i]->get_model() << std::endl;
}
void wyrejestruj(Pojazdy**& pojazdy, int& size) {
for (size_t i{ 0 }; i < size; i++)
delete pojazdy[i];
delete[] pojazdy;
size = 0;
pojazdy = NULL;
}
void wyrejestruj(Pojazdy**& pojazdy, int& size, int index) {
if (index < size) {
Pojazdy** temp = new Pojazdy * [size - 1];
short int j{ -1 };
for (size_t i{ 0 }; i < size; i++) {
if (i != index) {
j++;
temp[j] = pojazdy[i];
}
}
delete[] pojazdy;
--size;
pojazdy = temp;
}
else
std::cout << "Pamiec zwolniona!" << std::endl;
}
void d_pojazd(Pojazdy**& pojazdy, int& size) {
Pojazdy** temp = new Pojazdy * [size + 1];
if (size == 0)
temp[size] = new Pojazdy;
else {
for (int i{ 0 }; i < size; i++)
temp[i] = pojazdy[i];
delete[] pojazdy;
temp[size] = new Pojazdy;
}
++size;
pojazdy = temp;
}
I used #ifndef, #define, #endif and #pragma once, but none of them work. I will be really grateful for every code, I am already tired of this second hour. And forgive the non-English variables and function names for them - it's university code, so I didn't feel the need.

Answer 1

Move the functions below outside the class declaration.
void wyrejestruj(Pojazdy**& pojazdy, int& size, int index);
void print(Pojazdy** pojazdy, int size);
void Petla(Pojazdy**& p, int& size);
Or make them static and call like Pojazdy::print(poj, size);.

Answer 2

You declared a non-static member function print in the class definition
class Pojazdy
{
public:
// ...
void print(Pojazdy** pojazdy, int size);
//...
but you are trying to call it as a stand-alone function in main
print(poj, size);
So the compiler issues an error.
The declaration of the function as a stand alone function that at the same time is its definition in the file pojazdy.cpp is not visible in the module with main because this module includes only the header with the class declaration.
You should decide whether this function should be a member function of the class or a stand alone function.

Answer 3

You are not calling your member functions correctly. print can only be called on an object of type Pojazdy, so you need to do something like:
Pojazdy** poj;
int size{ 0 }, index{ 0 };
Pojazdy x; // Creates an object of Pojazdy called z
x.print(poj,size); // Calls the print method on x
Alternatively, if you don't want to have to declare an object, you could make the method static and just call it on the class.
In the .h file:
static void print(Pojazdy** pojazdy, int size);
And then in main:
Pojazdy** poj;
int size{ 0 }, index{ 0 };
Pojazdy::print(poj, size); // Calls the print method on the class

Answer 4

You put your function prototypes in the wrong place. They should be after the class decalration.
class Pojazdy
{
...
};
void print(Pojazdy** pojazdy, int size);
void wyrejestruj(Pojazdy**& pojazdy, int& size);
etc.
print is not a member of the Pojazdy class, so it's wrong to put the prototype inside the Pojazdy class declaration.