c++ thermometer with classes error messages - c++

Question

I know the thermometer problems have been done to death but I thought I would give this a shot.
I keep getting the error messages "use of undeclared identifier 'converterc'" and "use of undeclared identifier 'converterf'". Any ideas?
Spike
#include <iostream>
#include "converters.h"
using namespace std;
int main()
{
int degree;
int weehoo;
cout<<"\n\n\n\t\t Enter the temperature : ";
cin>>degree;
cout<<"\n\n\t\t If the temperature is in Celsius enter 0, if Farenheit enter 1 :";
cin>>weehoo;
if (weehoo==0)
{
cout<<"\n\n\t\tThe temperature in Farenheit is "<<converterc(degree,weehoo)<<endl;
}
else
{
cout<<"\n\n\t\tThe temperature in Celsius is "<<converterf(degree,weehoo)<<endl;
}
return 0;
}
#ifndef __again_converters_h
#define __again_converters_h
#endif
#pragma once
class Thermometer
{
private:
float degreeC; //celcius
float degreeF; //farenheit
public:
void setCelcius (float c) {degreeC=c;}
void setFarenheit (float f) {degreeF=f;}
float getCelcius (void){return degreeC;}
float getFarenheit (void){return degreeF;}
Thermometer (float degree=0,float f=0, float c=0,float outtemp=0);
float converterc(int degree,int weehoo);
float converterf(int degree,int weehoo);
};
converters.cpp file
#include "converters.h"
float Thermometer::converterf(int degree,int weehoo)
{
degreeC=((degree-32) * (.5556));
return degreeC ;
}
float Thermometer::converterc(int degree,int weehoo)
{
degreeF=((1.8)*degree)+32;
return degreeF;
}

Answer 1

converterc and converterf are member function of the class Thermometer but you're calling them without a Thermometer instance.
How about creating a Thermometer instance in your main?
Thermometer tm;
tm.converterc(degree, weehoo);

Answer 2

converterc and converterf are functions in your class. This means they are there to be called on an object being an instance of this class or class derived from this.
class Thermometer
{
private:
float degreeC; //celcius
float degreeF; //farenheit
//...
public:
float converterc(int degree,int weehoo);
float converterf(int degree,int weehoo);
};
int degree = 1;
int weehoo = 2;
Thermometer t; //initialize it properly if this is needed before calling functions
float f = t.converterc(degree,weehooo);
using these functions in the way you did this:
float f = converterc(degree,weehooo);
is possible as:
float f = Thermometer::converterc(degree,weehooo);
but then they have to be static what means they don't have this pointer and are common to whole class (still you can call them using an instance of class but it is not necessary):
class Thermometer
{
private:
float degreeC; //celcius
float degreeF; //farenheit
//...
public:
static float converterc(int degree,int weehoo);
static float converterf(int degree,int weehoo);
};