Koodiarvo

Koodiarvo is the Finnish term for the numerical value assigned to a symbol, element, or entity within a coding system. It functions as a basic unit of representation in data, enabling storage, processing, and communication across software and networks. In practice, koodiarvo may describe a character’s code point in a character encoding, an application's exit or error code, or a numeric status indicator in a protocol.

In character encoding, each character corresponds to a code value. For example, in Unicode the capital letter A has the code point U+0041, which equals 65 in decimal. Encodings such as UTF-8 translate this code point into one or more bytes. A code value can be interpreted differently depending on whether one speaks of code points, code units, or bytes; the abstract code point is distinct from its encoded representation.

In software and networking, koodiarvo is used whenever a numeric value identifies a condition or object. Common examples include exit codes from programs (0 indicating success, non-zero indicating failure) and protocol status codes (such as HTTP 200 for success, 404 for not found). The precise interpretation of a koodiarvo is defined by the surrounding encoding or protocol.

Related topics include Unicode code point, ASCII, UTF-8, and HTTP status code.