Glossary A–ZLetter J
JSON
JSON is a text-based data format in which data is written as name and value pairs and as lists, so that both people and programs can read it.
The abbreviation stands for “JavaScript Object Notation”; today the format is used independently of that programming language.
In screen networks, JSON is the usual exchange format for interfaces. A weather service supplies temperature and forecast as JSON, a calendar the bookings of a room, a management system a player's schedule. Templates and widgets read the values and put them in the right place on screen. JSON knows strings, numbers, true and false values, lists, nested objects and the null value.
JSON only describes the form of the data, not its meaning. Which fields exist and what they mean is defined by each interface; without its documentation the format is of little use. Operators should make sure that a field that suddenly goes missing or is empty does not lead to a blank or broken screen. Dates and time zones are not standardised in JSON and are a frequent source of errors.