Reading and Writing Text Files in C++

It is very easy to read from or write to a text file. Simply use the << and >> operators the same way you do when performing console I/O, except that instead of using cin and cout, substitute a stream that is linked to a file. For example, this program creates a short inventory file that contains each item's name and its cost:
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
ofstream out("INVNTRY"); // output, normal file
if(!out) {
cout << "Cannot open INVENTORY file.\n";
return 1;
}
out << "Radios " << 39.95 << endl;
out << "Toasters " << 19.95 << endl;
out << "Mixers " << 24.80 << endl;
out.close();
return 0;
}

The following program reads the inventory file created by the previous program and displays its contents on the screen:
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
ifstream in("INVNTRY"); // input
if(!in) {
cout << "Cannot open INVENTORY file.\n";
return 1;
}
char item[20];
float cost;
in >> item >> cost;
cout << item << " " << cost << "\n";
in >> item >> cost;
cout << item << " " << cost << "\n";
in >> item >> cost;
cout << item << " " << cost << "\n";
in.close();
return 0;
}