The objects and classes in this appendix support reading and writing to the console, as well as to files and strings. To read and write to the console, include <iostream>:
#include <iostream>cout << "Hello, world." << endl;
To write data to a string, include <sstream>. String streams support a member function (in addition to the ones listed here), str, which returns the data in string format.
#include <sstream>stringstream s_out;s_out << "The value of i answer is " << i << endl;string s = s_out.str()
The objects listed in Table G.1 provide predeclared streams to which to read or write text to the console. Each of them supports the appropriate stream operator (<< or >>). For example: