File Processing

#include <iostream>
#include <iomanip>
#include <fstream>

using namespace std;

void dataInput(){
    cout<<"\nFile opened for writing!\n";
	char file[] = "myNums.dat";
	ofstream outfile(file);
	double num;
	cout<<"Enter next number (-1 to quit): ";cin >> num;
	while(num!=-1){
		outfile<<num<<endl;
		cout<<"Enter next number (-1 to quit): ";cin >> num;
	}

	outfile.close();

    cout<<"\nFile has been closed for writing!\n";

}

double calcAverage(double total, int count){
	return total/count;
}

double displayData() {

	char file[] = "myNums.dat";
	ifstream infile(file);
	double total =0, num; int count=0;

	cout<<"\nFile opened for reading!\n";
	while(infile>>num)	{
		cout<<num<<endl;
		cout.width(2);
		total += num;
		count += 1;
	}
	infile.close();

    cout<<"\nFile has been closed for reading!\n";

	return calcAverage(total,count);
}

int main(){

	dataInput();

	double average = displayData();

	cout<<setprecision(2)<<fixed<<showpoint;
	cout<<"The average value read is " << average << endl;

	return 0;
}