# json(3tcl) 1.1.2 json "JSON"

## Name

json - JSON parser

## Table Of Contents

## Synopsis

- package require Tcl 8.4
- package require json ?1.1.2?

- ::json::json2dict txt

## Description

The json package provides a simple Tcl-only library for parsing the JSON http://www.json.org/ data exchange format as specified in RFC 4627 http://www.ietf.org/rfc/rfc4627.txt. There is some ambiguity in parsing JSON because JSON has type information that is not maintained by the Tcl conversion. The json package returns data as a Tcl dict. Either the dict package or Tcl 8.5 is required for use.

## COMMANDS

::json::json2dict txt

  Parse JSON formatted text txt into a Tcl dict and return the value.

## EXAMPLES

An example of a JSON array converted to Tcl. A JSON array is returned as a single item with multiple elements.

    [
        {
           "precision": "zip",
           "Latitude":  37.7668,
           "Longitude": -122.3959,
           "Address":   "",
           "City":      "SAN FRANCISCO",
           "State":     "CA",
           "Zip":       "94107",
           "Country":   "US"
        },
        {
           "precision": "zip",
           "Latitude":  37.371991,
           "Longitude": -122.026020,
           "Address":   "",
           "City":      "SUNNYVALE",
           "State":     "CA",
           "Zip":       "94085",
           "Country":   "US"
        }
    ]
    =>
    {Country US Latitude 37.7668 precision zip State CA City {SAN FRANCISCO} Address {} Zip 94107 Longitude -122.3959} {Country US Latitude 37.371991 precision zip State CA City SUNNYVALE Address {} Zip 94085 Longitude -122.026020}

An example of a JSON object converted to Tcl. A JSON object is returned as a multi-element list (a dict).

    {
        "Image": {
            "Width":  800,
            "Height": 600,
            "Title":  "View from 15th Floor",
            "Thumbnail": {
                "Url":    "http://www.example.com/image/481989943",
                "Height": 125,
                "Width":  "100"
            },
            "IDs": [116, 943, 234, 38793]
        }
    }
    =>
    Image {IDs {116 943 234 38793} Thumbnail {Width 100 Height 125 Url http://www.example.com/image/481989943} Width 800 Height 600 Title {View from 15th Floor}}

## Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category json of the Tcllib SF Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

## Keywords

data exchange, exchange format, javascript, json

## Category

CGI programming

## Copyright

Copyright © 2006 ActiveState Software Inc.
Copyright © 2009 Thomas Maeder, Glue Software Engineering AG