JSON (JavaScript Object Notation)

  • format for text
  • used to transmit data between different programs
  • can represent all essential data types, i.e. number, boolean, string, array, object, null
  • doesn’t support any other data types, e.g. function, date, regular expression, and undefined etc. ❗
  • file type .json, MIME type application/json

Syntax

  • follows JS literal syntax, e.g. string literal, array literal, object literal, etc.
  • whitespace is ignored
  • number: no leading zeros or trailing dots
  • string: double quotation marks only, escape chars are allowed
  • object: keys as strings, no methods since they are functions
  • beware: only one missing comma makes JSON text invalid ❗️

JSON object type

  • JSON.parse(): converts string from JSON to data type, deserialisation
  • JSON.stringify(): converts data type to JSON string, serialisation

Resources