C++ using getline and stringstream with multiple classes and overloaded stream operator

Question

I'm working on a university assignment to read in data from a file and could really use some help!

The data file contains weather data and looks like:

31/03/2016 9:00,14.6,175,17,0,1013.4,1016.9,1017,0,68.2,6,512,22.7,24.1,25.5

The assignment requires a class to read and store the date, time and all the int/double values. I have to use a date class to read the date, a time class to read the time and the WeatherData class brings it all together using overloaded stream operator.

I'm unit testing the WeatherData class (which will be used in an array of WeatherData classes) with a datafile that includes the date, time and just one double variable: 31/03/2016 9:00,14.6

The output I get is: 31/3/2016 0:0 0

I've unit tested the Date and Time classes and they work as expected. I can't see why it fails after the date. Any help would be greatly appreciated!

TestWeatherData.cpp

#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <cstdlib>
#include "../Practice/date.h"
#include "../Practice/time.h"
#include "../Practice/weatherdata.h"

using namespace std;

istream & operator >>( istream & input, Date & D )
{
  string temp;
  string convertToInt;
  int tempDay;
  int tempMonth;
  int tempYear;

  getline(input, temp);
  stringstream ss(temp);
  getline(ss, convertToInt, '/');
  tempDay = atoi(convertToInt.c_str());
  D.SetDay(tempDay);
  getline(ss, convertToInt, '/');
  tempMonth = atoi(convertToInt.c_str());
  D.SetMonth(tempMonth);
  getline(ss, convertToInt);
  tempYear = atoi(convertToInt.c_str());
  D.SetYear(tempYear);

  return input;
}

ostream & operator <<( ostream & os, const Date & D )
{

  os << D.GetDay() << "/" << D.GetMonth()
     << "/" << D.GetYear();

  return os;
}

istream & operator >>( istream & input, Time & T )
{
  string temp;
  string convertToInt;
  int tempHours;
  int tempMinutes;

  getline(input, temp);
  stringstream ss(temp);
  getline(ss, convertToInt, ':');
  tempHours = atoi(convertToInt.c_str());
  T.SetHours(tempHours);
  getline(ss, convertToInt);
  tempMinutes = atoi(convertToInt.c_str());
  T.SetMinutes(tempMinutes);

  return input;
}

ostream & operator <<( ostream & os, const Time & T )
{

  os << T.GetHours() << ":" << T.GetMinutes();

  return os;
}

istream & operator >>( istream & input, WeatherData & W )
{
  string temp;
  string convertToDouble;
  Date tempDate;
  Time tempTime;
  double tempDP;

  input >> tempDate >> tempTime;
  W.setDate(tempDate);
  W.setTime(tempTime);
  getline(input, temp);
  stringstream ss(temp);
  getline(ss, convertToDouble);
  tempDP = atof(convertToDouble.c_str());
  W.setDP(tempDP);

  return input;
}

ostream & operator <<( ostream & os, const WeatherData & W )
{

  os << W.getDate() << ' ' << W.getTime() << ' ' << W.getDP();

  return os;
}

int main()
{
    ifstream infile( "data.txt" );
    if( !infile ) return -1;

    WeatherData W;

    infile >> W;

    cout << W;

    return 0;
}

http://idownvotedbecau.se/toomuchcode/ please include a [minimal example](https://stackoverflow.com/help/mcve). — Thomas Flinkow, Apr 26 '18 at 18:46
By way of a heavy hint: each of your `operator>>` overloads for the `Date` and `Time` classes calls `std::getline` on the input stream -- but the data for both is actually on the same line. — G.M., Apr 26 '18 at 19:22
I'm not sure what you mean G.M. Sorry, I'm very new to this! Do you mean the data in the text file? If so, I'm not allowed to change the structure of the text file. — Jason Collier, Apr 27 '18 at 04:02
Once you get the date the entire line has been read and can't be used again so the time has nothing to read from. You can only use getline on input once per line. — Jerry Jeremiah, Apr 27 '18 at 04:13

score 0 · Answer 1 · answered Apr 27 '18 at 04:36

Thanks Jerry Jeremiah and G.M! I can see now I was reading the whole line in the Date class so on the first getline I added a delimiter of a space character. In the Time class on the first getline I added a delimiter of a comma. Now it works as expected!

  getline(input, temp, ' '); // added delimiter here
  stringstream ss(temp);
  getline(ss, convertToInt, '/');
  tempDay = atoi(convertToInt.c_str());
  D.SetDay(tempDay);
  getline(ss, convertToInt, '/');
  tempMonth = atoi(convertToInt.c_str());
  D.SetMonth(tempMonth);
  getline(ss, convertToInt);
  tempYear = atoi(convertToInt.c_str());
  D.SetYear(tempYear);
  return input;

  getline(input, temp, ','); // added delimiter here
  stringstream ss(temp);
  getline(ss, convertToInt, ':');
  tempHours = atoi(convertToInt.c_str());
  T.SetHours(tempHours);
  getline(ss, convertToInt);
  tempMinutes = atoi(convertToInt.c_str());
  T.SetMinutes(tempMinutes);
  return input;

C++ using getline and stringstream with multiple classes and overloaded stream operator

1 Answers1