Streams: Predefined Streams

Streams: Predefined Streams

Applies To: C++Builder 1 or higher
Category: C++ Language

The following predefined standard streams are automatically opened when the programs starts:

cin : controls input

cout: controls output

cerr: controls error output

clog: controls log output (buffer associated with cerr)

There're also the corresponding wide character versions: wcin, wcout, wcerr and wclog.

For example, to display text on the screen, use cout with the << operator:

cout <<< "This is a text";

cout <<< "\nThis is a number: " <<< 5;

Escape sequences

You can use the backslash to insert special characters:
· \a: Bell
· \b: Backspace
· \n: New line
· \t: Horizontal tab
· \\: Backslash
· \?: Question mark
· \': Single quotation
· \": Double quotations

To read data from the keyboard, use cin with the >> operator. For example:

int number;

cout <<< "Enter number: ";

cin >> number;

cout <<< "Your number is: " <<< number;

In order to use these streams, you must include the appropriate header and namespace.