Question

I am trying to open a file which normally has content, for the purpose of testing i will like to initialize the program without the files being available/existing so then the program should create empty ones, but am having issues implementing it. This is my code originally

void loadFiles() {
fstream city;
    city.open("city.txt", ios::in);
fstream latitude;
    latitude.open("lat.txt", ios::in);
fstream longitude;
    longitude.open("lon.txt", ios::in);
while(!city.eof()){
    city >> cityName;
    latitude >> lat;
    longitude >> lon;
    t.add(cityName, lat, lon);
}
city.close();
latitude.close();
longitude.close();
}

I have tried everything i can think of, ofstream, ifstream, adding ios::out all all its variations. Could anybody explain me what to do in order to fix the problem. Thanks!

Answer 1

You have posted code for reading files, not creating empty ones – you need t expand your question in this regard. And what you have posted is not good code for reading. The eof() function detects end of file following a read, not before one – basically, you should almost never use it. Instead, you should test the success of each read:

while( (city >> cityName) && (latitude >> lat) && (longitude >> lon) {
    t.add(cityName, lat, lon);
}

Also, if you want to create an input stream, why not do so explicitly using an ifstream object:

ifstream city( "city.txt" );

No need to mess around with ios flags. You should really test if the open worked too:

if ( ! city.is_open() ) {
   throw "open failed" ;   // or whatever
}