In
character encoding terminology, a code point, codepoint or code position is a numerical value that maps to a specific
character
Character or Characters may refer to:
Arts, entertainment, and media Literature
* ''Character'' (novel), a 1936 Dutch novel by Ferdinand Bordewijk
* ''Characters'' (Theophrastus), a classical Greek set of character sketches attributed to The ...
. Code points usually represent a single
grapheme—usually a letter, digit, punctuation mark, or whitespace—but sometimes represent symbols,
control characters
In computing and telecommunication, a control character or non-printing character (NPC) is a code point (a number) in a character set, that does not represent a written symbol. They are used as in-band signaling to cause effects other than the ...
, or formatting. The set of all possible code points within a given encoding/character set make up that encoding's ''codespace''.
For example, the character encoding scheme
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...
comprises 128 code points in the range 0
hex
Hex or HEX may refer to:
Magic
* Hex, a curse or supposed real and potentially supernaturally realized malicious wish
* Hex sign, a barn decoration originating in Pennsylvania Dutch regions of the United States
* Hex work, a Pennsylvania Dutch ...
to 7F
hex,
Extended ASCII
Extended ASCII is a repertoire of character encodings that include (most of) the original 96 ASCII character set, plus up to 128 additional characters. There is no formal definition of "extended ASCII", and even use of the term is sometimes critic ...
comprises 256 code points in the range 0
hex to FF
hex, and
Unicode comprises code points in the range 0
hex to 10FFFF
hex. The Unicode code space is divided into seventeen
planes
Plane(s) most often refers to:
* Aero- or airplane, a powered, fixed-wing aircraft
* Plane (geometry), a flat, 2-dimensional surface
Plane or planes may also refer to:
Biology
* Plane (tree) or ''Platanus'', wetland native plant
* ''Planes' ...
(the basic multilingual plane, and 16 supplementary planes), each with (= 2
16) code points. Thus the total size of the Unicode code space is 17 × = .
Definition
The notion of a code point is used for abstraction, to distinguish both:
* the number from an encoding as a sequence of