error: undefined reference to class::method (main, header file, source code) - c++

Question

Source File:
#include "WeatherForecaster.h"
#include <iostream>
using namespace std;
WeatherForecaster::WeatherForecaster(string d, string fd, int h, int l, int hum,int avgw, string avgwd, int maxw, string maxwd, double p){
string day=d;
string forecastDay=fd;
int highTemp=h;
int lowTemp =l;
int humidity=hum;
int avgWind= avgw;
string avgWindDir=avgwd;
int maxWind=maxw;
string maxWindDir= maxwd;
double recip=p;
}
WeatherForecaster::WeatherForecaster(){
//dtor
}
void AddDaytoData(ForecastDay){
}
Header File:
#ifndef WEATHERFORECASTER_H
#define WEATHERFORECASTER_H
#include <iostream>
using namespace std;
struct ForecastDay{
std::string day;
std::string forecastDay;
int highTemp;
int lowTemp;
int humidity;
int avgWind;
std::string avgWindDir;
int maxWind;
std::string maxWindDir;
double precip;
};
class WeatherForecaster
{
public:
WeatherForecaster(string, string, int, int,
int,int, string, int, string , double );
WeatherForecaster();
void addDayToData(ForecastDay);
void printDaysInData(); //prints the unique dates in the data
void printForecastForDay(std::string);
void printFourDayForecast(std::string);
double calculateTotalPrecipitation();
void printLastDayItRained();
void printLastDayAboveTemperature(int);
void printTemperatureForecastDifference(std::string);
void printPredictedVsActualRainfall(int);
std::string getFirstDayInData();
std::string getLastDayInData();
protected:
private:
int arrayLength;
int index;
ForecastDay yearData[984]; //data for each day
};
#endif // WEATHERFORECASTER_H
ERROR: My error happens when I declare try to reach a function in my source file after declaring an instance of the class Weather Function.
ex:
WeatherForecaster wf;
wf.AddDayToData();
//undefined reference to 'WeatherForecaster::AddDaytoData'
I am not entirely sure where the lack of referencing is happening, also I have the header included in main, as well as all other relevant additions.
Edit: I added a function as an example

Answer 1

In your cpp file you need to scope your member function definition
WeatherForecaster::AddDayToData(ForecastDay)
instead of
AddDayToData(ForecastDay)
Also in your call you must pass an argument since it's not optional