#include <fstream>            • <fstream> header file
using namespace std;         – Use ifstream for input
int main()                         – Use ofstream for output
{
ifstream ifs;                      
ifs.open(“in.txt�);              • Other methods 
ofstream ofs(“out.txt�);     – open, is_open, close    
if (ifs.is_open() &&            – getline
ofs.is_open()){                – seekg, seekp  
int i;                              • File modes
ifs >> i;                          – in, out, ate, app, trunc, binary
ofs << i; 
}
ifs.close();
 ofs.close();
return 0;
}

#include <iostream>         • <sstream> header file
#include <fstream>          – Use istringstream for input
#include <sstream>          – Use ostringstream for output
using namespace std;       
int main() {                      • Useful for scanning input
ifstream ifs(“in.txt�);          – Get a line from file into string
if (ifs.is_open())                – Wrap string in a stream
{string line1, word1;          – Pull words off the stream
getline(ifs, line1);              • Useful for formatting output
istringstream iss(line1);      – Use string as format buffer
iss >> word1;                   – Wrap string in a stream
cout << word1 << endl;     – Push formatted values into stream
}                                    – Output formatted string to file
return 0;
}