Thread: error compiling

Hello!

This is my first time making classes and I have some problems compiling and running my program.

My program consists of 3 parts:
- main.cc
- calculation.cc
- calculation.h

in the Calculation.h:

#ifndef _CALCULATION_H_
#define _CALCULATION_H_

#include <string>
using namespace std;

class Calculation {

public:
Calculation ();
virtual ~Calculation();
void getSize();

protected:
int a, b;
};
#endif

in Calculation.cc:
#include <iostream>
#include <string>
#include <vector>
#include "Calculation.h"

Calculation::Calculation() {a=0; b=0;}
Calculation::~Calculation() {}

void getSize() {
cout << "hi" << endl;
}


in the main.cc:
#include <iostream>
#include <string>
#include "Calculation.h"
using namespace std;

int main( int argc, char *argv[] ) {

Calculation calc;
calc.getSize();

}

I'm compiling and linking them this way:
g++ -c Calculation.cc
g++ -c main.cc
g++ Calculation.o main.o -o test

however, when executing "g++ Calculation.o main.o -o test", this error occurs:
Undefined first referenced
symbol in file
Calculation::getSize(void) /var/tmp/ccebkQ3K.o
ld: fatal: Symbol referencing errors. No output written to test
collect2: ld returned 1 exit status

Does anyone have any idea what this error is trying to say?
I'm so confused~~ Can anyone point me in the right direction?

Thanks a lot!!

Try:

void Calculation::getSize() {
cout << "hi" << endl;
}

You forgot to scope getSize to the class in your implementation, now it's a global function, and you are calling a member function.

Thanks a lot!

what are code tags ?