Editing C (programming language) (section)

=== Character set ===
The basic C source character set includes the following characters:
* Lowercase and uppercase letters of the [[ISO basic Latin alphabet]]: <code>a</code>–<code>z</code>, <code>A</code>–<code>Z</code>
* Decimal digits: <code>0</code>–<code>9</code>
* Graphic characters: <code>! " # % & ' ( ) * + , - . / : ; < = > ? [ \ ] ^ _ { | } ~</code>
* [[Whitespace character]]s: ''[[Space (punctuation)|space]]'', ''[[horizontal tab]]'', ''[[vertical tab]]'', ''[[form feed]]'', ''[[newline]]''

The ''newline'' character indicates the end of a text line; it need not correspond to an actual single character, although for convenience C treats it as such.

Additional multi-byte encoded characters may be used in [[string literal]]s, but they are not entirely [[Software portability|portable]]. Since [[C99]] multi-national Unicode characters can be embedded portably within C source text by using <code>\uXXXX</code> or <code>\UXXXXXXXX</code> encoding (where <code>X</code> denotes a hexadecimal character).

The basic C execution character set contains the same characters, along with representations for [[Bell character|alert]], [[backspace]], and [[carriage return]]. [[Run time (program lifecycle phase)|Run-time]] support for extended character sets has increased with each revision of the C standard.