C++ Primer, Fifth Edition

1.2. A First Look at Input/Output

The C++ language does not define any statements to do input or output (IO). Instead, C++ includes an extensive standard library that provides IO (and many other facilities). For many purposes, including the examples in this book, one needs to know only a few basic concepts and operations from the IO library.

Most of the examples in this book use the iostream library. Fundamental to the iostream library are two types named istream and ostream , which represent input and output streams, respectively. A stream is a sequence of characters read from or written to an IO device. The term stream is intended to suggest that the characters are generated, or consumed, sequentially over time.