下面的C++代碼將用戶輸入的信息寫入到afile.dat，然后再通過程序讀取出來輸出到屏幕

#include <fstream>

include <iostream>
using namespace std;
int main ()
{
char data[100];
// open a file in write mode.
   ofstream outfile;
   outfile.open("afile.dat");
cout << "Writing to the file" << endl;
   cout << "Enter your name: ";
   cin.getline(data, 100);
// write inputted data into the file.
   outfile << data << endl;
cout << "Enter your age: ";
   cin >> data;
   cin.ignore();
// again write inputted data into the file.
   outfile << data << endl;
// close the opened file.
   outfile.close();
// open a file in read mode.
   ifstream infile;
   infile.open("afile.dat");
cout << "Reading from the file" << endl;
   infile >> data;
// write the data at the screen.
   cout << data << endl;
// again read the data from the file and display it.
   infile >> data;
   cout << data << endl;
// close the opened file.
   infile.close();
return 0;
}</pre> 

 程序編譯執行后輸出如下結果
$./a.out
Writing to the file
Enter your name: Zara
Enter your age: 9
Reading from the file
Zara
9