Thread: Simple function call in main not working ( Classes)

So I have 2 files linked: Fraction.h and main.cpp

Fraction.h contains function definitions and declarations

main.cpp is where int main is:

Code:

Class Fraction
int a;
public:                                                     
Fraction(int a, int b) // initialized constructor            
{ 
     a= 0;
 }       
          int get ()        
         {   
         return (a+1);
        }

Code:

#include "Fraction.h"
int main ()
{
int a,b;
cin >> a>>b;
Fraction test (a,b);
cout << test. get() ;
}


error: undefined reference to Fraction :: Fraction (int, int)

In the header file, i declared int a and set it to 0. When i call the object test.get() in main, the result should be 1. Instead it's giving me the error: I think its saying somehow my constructor is undefined? But i dont see where. It's such a simple program.

This compiles for me:

Code:

#include <iostream>

class Fraction
{
public:
    Fraction(int a, int b)
    {
        a = 0;
    }

    int get()
    {
        return a + 1;
    }
private:
    int a;
};

int main ()
{
    using namespace std;
    int a, b;
    cin >> a >> b;
    Fraction test(a, b);
    cout << test.get();
}

Your error sounds like a link error though. You need to post your actual code, not a retyped version that should not even compile.

Oh ok it works when i use a makefile.

Any ideas as to why it prints out junk values?

input: 1,2

output: -2113342424

The member access is private by default, so it makes no difference in this case, except that I prefer to declare the public interface first where feasible.

Originally Posted by tmac619619

Any ideas as to why it prints out junk values?

You decided to name your constructor parameter with the same name as a member variable. Therefore, when you assigned to a in the constructor body, you were assigning to the parameter, not the member variable.