Question

just wanted to start some C++ and created these simple class:

Ellipsoid.h

#ifndef __Ellipsoid__Ellipsoid__
#define __Ellipsoid__Ellipsoid__

#include <iostream>
#include <cassert>


class Ellipsoid {
private:
    double axisA;
    double flatteningF;

public:
    Ellipsoid() {};
   Ellipsoid(double aIn, double fIn);
    double getAxisA();
    double getFlatteningF();



};

#endif /* defined(__Ellipsoid__Ellipsoid__) */

Ellipsoid.cpp

#include "Ellipsoid.h"


Ellipsoid::Ellipsoid (double aIn, double fIn) : axisA(aIn), flatteningF(fIn) {};

int main() {
    std::cout << "bla";
    Ellipsoid el = Ellipsoid(44.3, 32);
    double test = el.getAxisA();


    return 0;
}

as you can see nothing special here. i’m using xcode on osx10.8.
But when i run the programm i come to this error:
Undefined symbols for architecture x86_64:
“Ellipsoid::getAxisA()”, referenced from:
_main in Ellipsoid.o
ld: symbol(s) not found for architecture x86_64
and i really can’t figure out whats wrong. tried to set the architecture to 32 bit but this won’t work neither

Answer 1

The definition of the Ellipsoid::getAxisA() function is missing. You must define somewhere. Right now you only have a declaration, not a definition. The definition could look something like this:

double Ellipsoid::getAxisA() { return axisA; }

And would live in Ellipsoid.cpp.