Thread: Opening file and loading data into Vector

I'm having trouble trying to load data from a file.
I have an array that I'm saving to a file using this function:

Code:

void option_6() { //Save To File
	cout << "\nEnter the name you'd like to save your file as: ";
	cin >> FileName;
	
	outFile.open(FileName, ios::out);
	outFile << station.size() << "\n";
	for(int i = 0; i < station.size(); i++) {
		outFile << station[i].StationDesignation << "\n" << station[i].TemperatureF << "\n" << station[i].TemperatureC << "\n" << station[i].DailyCount << "\n";
	}
	outFile << Average << "\n" << AverageC;
	outFile.close();
	
	cout << "File saved as " << FileName << endl;
}

The outputted file is:

Code:

2
Fremont
55
12.7778
5.5
Tustin
55
12.7778
5.5
55
12.7778

The first line is the size of the vector (stationSize)
lines 2-5 and 6-9 are elements of the vector (station[i].StationDesignation, station[i].TemperatureF, station[i].TemperatureC, and station[i].DailyCount)
and 10-11 are two more variables (Average and AverageC).
*The data was generated from previous parts of the program.*

I'm trying to read the data from the file back into those same variables using the following function, but I'm not sure exactly what I'm doing wrong.

Code:

void option_7() { //Read From File
	int stationSize;
	cout << "Enter the name of the file you want to open: ";
	cin >> FileName;
	
	outFile.open(FileName, ios::in);
	outFile >> stationSize;
	station[stationSize];
	for(int i = 0; i < station.size(); i++) {
		outFile >> station[i].StationDesignation >> station[i].TemperatureF >> station[i].TemperatureC >> station[i].DailyCount;
	}
	outFile >> Average >> AverageC;
	outFile.close();
	
	cout << "Opened " << FileName << "." << endl;
}

I've attached the code for the whole program, if it'll help. Although I must warn, it's pretty messy.

What do you think "station[stationSize]" is supposed to do? Don't you want to create a vector of stations?

Yeah. the size of the vector changes dynamically as more stations are added on.
But as I'm loading the file for the first time, the vector has nothing inside it, so I thought I needed to declare the size of it before loading data (like Temperature and DailyCount) back in.

Originally Posted by soopah256

Yeah. the size of the vector changes dynamically as more stations are added on.
But as I'm loading the file for the first time, the vector has nothing inside it, so I thought I needed to declare the size of it before loading data (like Temperature and DailyCount) back in.

Then do so. Hint: you affect the size of the variable by using something like .resize().

Thanks for your help! I got it to work with the resize() function.