Json is a value type that represents a JSON data structure.

Literal syntax

JSON structures can be written directly in Zing code. If the JSON key is a valid Zing property identifier (like name or albums below) it can be included directly, otherwise it will need to be enclosed in quotes.

Json artist = {
    name: "Rihanna",
    "birth date": "20/02/1988",
    "Active": true,
    albums: ["Good Girl Gone Bad", "Rated M"]

As "birth date" (contains a space) and "Active" (begins with an uppercase letter) are not valid property identifiers, they must be quoted.

Reading and writing values

Json values can be read or written directly in Zing. When a Json key is a valid Zing identifier it can be accessed using dot notation:

// Logs "Rihanna"
artist.realname = "Robyn Rihanna Fenty"

When a Json key is not a valid Zing identifier, subscript syntax can be used:

System.log(artist["birth date"], artist.albums[0])
// Logs "20/02/1988 Good Girl Gone Bad"
artist.albums[1] = "Rated R"


Compatible types, such as Int and String, are transparently converted to their JSON equivalent on assignment.

function makeUser(String firstName, String lastName, Int height) 
    -> Json {
    return {
        name: {
            first: firstName,
            last: lastName
        height: height,
        heightInches: height / 2.54

static function Json.parse(String string) → Json

static async function Json.parseAsync(String string) → Json

Parses string in JSON format, and returns the resulting Json value.

static function Json.stringify(Json json) → String

Convert the JSON value to a serialized string form, suitable for transmission or storage.

Json json = {
    firstname: "Jon",
    surname: "Snow"

// {"firstname":"Jon","surname":"Snow"}

static async function Json.load(Url url) → Json

static async function Json.load(Http.Request request) → Json

Load Json from a url or request.

The url can be a local file in your project, or a network URL.

function type() → Json.Type

Returns the underlying type of the Json value.

The possible types are:








function isUndefined() → Bool

function isNull() → Bool

function isBool() → Bool

function isNumber() → Bool

function isString() → Bool

function isDictionary() → Bool

function isArray() → Bool

Returns true if the Json value is of the corresponding type, otherwise false.

function toBool() → Bool

function toInt() → Int

function toNumber() → Float

function toString() → String

function toDictionary() → Dictionary<String, Json>

function toArray() → Array<Json>

Convert the Json value into the corresponding native Zing type.

function length() → Int

If the value is a Json array, returns the array length. Otherwise returns 0.

function keys() → Array<String>

If value is a Json dictionary, returns an array of key names. Otherwise returns an empty array.

function remove(Int index)

function remove(String member)

Remove the array index or dictionary member.

function append(Json value)

function prepend(Json value)

function insert(Int index, Json value)

If the Json value is an array, these methods append, prepend or insert a new value. If the value is not an array, they have no effect.