Undefined symbols for architecture x86_64: c++

Question

i'me getting the error in xcode Undefined symbols for architecture x86_64: "Restaurant::Restaurant()", referenced from: _main in main.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

This is my code:

#include <iostream>
using namespace std;


class Restaurant
{
public:
    Restaurant();
    int getTables();
    int getTempStaff();
    int getPermStaff();
    string getShifts();
    string getMenu(string menu);
private:
    string Menu;
    int Tables;
    int TempStaff;
    int PermStaff;
    string Shifts[3];
};

string Restaurant::getMenu(string menu)
{
    Menu = menu;
    return menu;
}

int main()
{
    Restaurant mimmos;


    string Menu;
    cout<<"Menu: ";
    cin>>Menu;
    cout<<mimmos.getMenu(Menu);

    return 0;

}

Please help.

Answer 1

You have the following methods declared:

Restaurant();
int getTables();
int getTempStaff();
int getPermStaff();
string getShifts();
string getMenu(string menu);

.. and you've defined Restaurant::getMenu below. The problem here is that although you've declared Restaurant::Restaurant (the constructor), you haven't defined it.

But that's true of Restaurant::getShifts, why aren't you getting an error with that aswell?

It's because the constructor is automatically called when an object of that type is being created, like here:

//..
Restaurant mimmos;
//..

. You never actually end up trying to call Restaurant::getShifts (or the other non-constructor methods for that matter) so there's no error.

You can define the constructor to be default (which allows your compiler make a sensible one for you) as the other answer-er said or you can define your own, which is what you seem to want to do anyway.

Answer 2

class Restaurant {

    Restaurant() = default;
    ...
};

will give you the default constructor for Restaurant.