If you mean File I/O
ie, to be able to output to a text file... There are many tutorials about this, and think there is one on this site...
If you want to see how does it look like, here is an example:
Just read some tutorials for more detailes, like the modes you can open a file with, and you should also learn i/o in binary mode...
#include <fstream> //to use file i/o
#include <cstdlib> //To use exit();
using namespace std;
ofstream outFile("output.txt", ios::out);
if ( !outFile )
cerr << "Output file cannot be opened";
//here is where you output to the file.
outFile << "This is my first output to a file in C++";
And if you have any further questions, post them here...