JSON in JavaScript

Douglas Crockford [email protected]

2015-05-03

JSON is a light-weight, language independent, data interchange format. See http://www.JSON.org/

The files in this collection implement JSON encoders/decoders in JavaScript.

JSON became a built-in feature of JavaScript when the ECMAScript Programming Language Standard - Fifth Edition was adopted by the ECMA General Assembly in December 2009. Most of the files in this collection are for applications that are expected to run in obsolete web browsers. For most purposes, json2.js is the best choice.

json2.js: This file creates a JSON property in the global object, if there isn't already one, setting its value to an object containing a stringify method and a parse method. The parse method uses the eval method to do the parsing, guarding it with several regular expressions to defend against accidental code execution hazards. On current browsers, this file does nothing, preferring the built-in JSON object. There is no reason to use this file unless fate compels you to support IE8, which is something that no one should ever have to do again.

json_parse.js: This file contains an alternative JSON parse function that uses recursive descent instead of eval.

json_parse_state.js: This files contains an alternative JSON parse function that uses a state machine instead of eval.

cycle.js: This file contains two functions, JSON.decycle and JSON.retrocycle, which make it possible to encode cyclical structures and dags in JSON, and to then recover them. This is a capability that is not provided by ES5. JSONPath is used to represent the links. [http://GOESSNER.net/articles/JsonPath/]