6.4.3 Universal character names

Syntax

1

universal-character-name:

\u hex-quad

\U hex-quad hex-quad

hex-quad:

hexadecimal-digit hexadecimal-digit

hexadecimal-digit hexadecimal-digit

Constraints

2

A universal character name shall not specify a character whose short identifier is less than 00A0 other than 0024 ($), 0040 (@), or 0060 (‘), nor one in the range D800 through DFFF inclusive.[1]

Description

3

Universal character names may be used in identifiers, character constants, and string literals to designate characters that are not in the basic character set.

Semantics

4

The universal character name \Unnnnnnnn designates the character whose eight-digit short identifier (as specified by ISO/IEC 10646) is nnnnnnnn.[2] Similarly, the universal character name \unnnn designates the character whose four-digit short identifier is nnnn (and whose eight-digit short identifier is 0000nnnn).

Footnotes

[1]

The disallowed characters are the characters in the basic character set and the code positions reserved by ISO/IEC 10646 for control characters, the character DELETE, and the S-zone (reserved for use by UTF-16).

[2]

Short identifiers for characters were first specified in ISO/IEC 10646-1/AMD9:1997.