kodpunktrepresentation

Kodpunktrepresentation, or code point representation, describes how a character’s underlying numeric code point is expressed and stored in computing systems. In Unicode, a code point is a scalar value assigned to a character, ranging from U+0000 to U+10FFFF. The same code point can be written in several notations, such as hexadecimal U+XXXX or its decimal equivalent.

Code points are abstract values, not bytes. To be stored or transmitted, they must be encoded into a sequence of bytes using a specific encoding form. The most common encodings are UTF-8, UTF-16, and UTF-32. UTF-8 uses 1 to 4 bytes per code point and is backward compatible with ASCII. UTF-16 uses 2 bytes for most characters in the Basic Multilingual Plane and uses surrogate pairs to encode code points above U+FFFF. UTF-32 uses a fixed 4 bytes for every code point.

Examples: the Latin letter A has code point U+0041. The grinning face emoji has code point U+1F600. In UTF-8, U+0041 is encoded as 41, and U+1F600 as F0 9F 98 80; in UTF-16, U+0041 is 0041 and U+1F600 is D83D DE00; in UTF-32, U+0041 is 00000041 and U+1F600 is 0001F600.

In programming, code point representations appear as literals or escapes, for example U+0041 or \u0041 in source code, or \U0001F600 in languages that support extended escapes. Distinctions among code points, encodings, and glyph rendering underpin typography and internationalization.

See also Unicode, UTF-8, UTF-16, UTF-32.