Escape sequences

You can represent any member of the execution character set by an escape sequence. They are primarily used to put nonprintable characters in character and string literals. For example, you can use escape sequences to put such characters as tab, carriage return, and backspace into an output stream.

Escape character syntax

An escape sequence contains a backslash (\) symbol followed by one of the escape sequence characters or an octal or hexadecimal number. A hexadecimal escape sequence contains an x followed by one or more hexadecimal digits (0-9, A-F, a-f). An octal escape sequence uses up to three octal digits (0-7). The value of the hexadecimal or octal number specifies the value of the desired character or wide character.

Note: The line continuation sequence (\ followed by a new-line character) is not an escape sequence. It is used in character strings to indicate that the current line of source code continues on the next line.

The escape sequences and the characters they represent are:

Escape sequence	Character represented
\a	Alert (bell, alarm)
\b	Backspace
\f	Form feed (new page)
\n	New-line
\r	Carriage return
\t	Horizontal tab
\v	Vertical tab
\'	Single quotation mark
\"	Double quotation mark
\?	Question mark
\\	Backslash

The value of an escape sequence represents the member of the character set used at runtime. Escape sequences are translated during preprocessing. For example, on a system using the ASCII character codes, the value of the escape sequence \x56 is the letter V. On a system using EBCDIC character codes, the value of the escape sequence \xE5 is the letter V.

Use escape sequences only in character constants or in string literals. An error message is issued if an escape sequence is not recognized.

In string and character sequences, when you want the backslash to represent itself (rather than the beginning of an escape sequence), you must use a \\ backslash escape sequence. For example:

cout << "The escape sequence \\n." << endl;

This statement results in the following output:

The escape sequence \n.