How to take info from a text file and put it into a function and take the output and put it into a new file

[Programmingaddict]

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

  float rowAverage(float val1, float val2, float val3, float val4, float val5) 
{
  float sum = val1 + val2 + val3 + val4 + val5;
  float average = sum / 5.0;
  return average;
}

int main() 
{
  ifstream input("inputData.txt");
  ofstream output("averages.txt");
  
  float average, val1, val2, val3, val4, val5;
  //string fname, lname;
  
  //getline(fname, lname);
  
  while(!input.eof())
  {
  	
  	input >> val1 >> val2 >> val3 >> val4 >> val5;
  	rowAverage(val1, val2, val3, val4, val5);
  	output << rowAverage;
  	
  	
    
  }
  
    output.close();
	input.close();
	cout << "done";
	return 0;
}

[mbozzi]

Lines 28-29 should read

  	average = rowAverage(val1, val2, val3, val4, val5);
  	output << average << '\n';

Or simply
output << rowAverage(val1, val2, val3, val4, val5) << '\n';

You could get away with

#include <fstream>

int main() 
{
  std::ifstream input{"inputData.txt"};
  std::ofstream output{"averages.txt"};

  for (float a, b, c, d, e; input >> a >> b >> c >> d >> e; ) 
    output << ((a + b + c + d + e) / 5.0f) << '\n';
}

[Programmingaddict]

I wish I was allowed to do that, but he wanted the function but didn't tell us the parameters of how to write outputting information from a function to a file so thank you so much.

[seeplus]

Your read loop has an issue as eof() doesn't work the way you're thinking it is. eof() is only set once you try to read past eof - not when a read is successful but the read ends at end-of-file. It's normal to put the file extraction in the while loop. Also, there's no check that the input file has been opened OK.

#include <iostream>
#include <fstream>

using namespace std;

float rowAverage(float val1, float val2, float val3, float val4, float val5)
{
	return (val1 + val2 + val3 + val4 + val5) / 5.0;
}

int main()
{
	ifstream input("inputData.txt");

	if (!input.is_open())
		cout << "Cannot open input file\n";
	else {
		ofstream output("averages.txt");

		float average, val1, val2, val3, val4, val5;

		while (input >> val1 >> val2 >> val3 >> val4 >> val5)
			output << rowAverage(val1, val2, val3, val4, val5) << '\n';

		output.close();
		input.close();
	}

	cout << "done";
	return 0;
}