JSON

Overview

The JSON object contains static methods for parsing values from and converting values to JSON.

For more information see: JSON (MDN).

Methods Summarized

Type

Name

Summary

Parses a string as JSON and returns the parsed value.

Convert a value to JSON, optionally replacing values if a replacer function is specified, or optionally including only the specified properties if a replacer array is specified

Convert a value to JSON, optionally replacing values if a replacer function is specified, or optionally including only the specified properties if a replacer array is specified.

Methods Detailed

parse(text)

Parses a string as JSON and returns the parsed value.

Parameters

String text The string to parse as JSON. See the JSON object for a description of JSON syntax.

Returns: Object

Sample

JSON.parse('[1, 5, "false"]');

parse(text, reviver)

Parses a string as JSON and returns the parsed value.

Parameters

String text The string to parse as JSON. See the JSON object for a description of JSON syntax.
Function reviver A function, prescribes how the value originally produced by parsing is transformed, before being returned.

Returns: Object

Sample

var transformed = JSON.parse('{"p": 5}', function(k, v) { if (k === "") return v; return v * 2; });

stringify(value)

Convert a value to JSON, optionally replacing values if a replacer function is specified, or optionally including only the specified properties if a replacer array is specified

Parameters

Object value The value to convert to a JSON string.

Returns: String

Sample

JSON.stringify([1, "false", false])

stringify(value, replacer)

Convert a value to JSON, optionally replacing values if a replacer function is specified, or optionally including only the specified properties if a replacer array is specified. As a function, the replacer takes two parameters, the key and the value being stringified. Initially it gets called with an empty key representing the object being stringified, and it then gets called for each property on the object or array being stringified.

Parameters

Object value The value to convert to a JSON string.
Function replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.

Returns: String

Sample

function censor(key, value) {
 if (typeof(value) == "string") {
   return undefined;
 }
 return value;
}

var foo = {foundation: "Mozilla", model: "box", week: 45, transport: "car", month: 7};
var jsonString = JSON.stringify(foo, censor);

stringify(value, replacer, space)

Parameters

Object value The value to convert to a JSON string.
Function replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.
Number space The space argument may be used to control spacing in the final string (causes the resulting string to be pretty-printed). If it is a number, successive levels in the stringification will each be indented by this many space characters (up to 10). If it is a string, successive levels will indented by this string (or the first ten characters of it).

Returns: String

Sample

JSON.stringify({ uno: 1, dos : 2 }, null, '\t')

stringify(value, replacer, space)

Parameters

Object value The value to convert to a JSON string.
Function replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.
String space The space argument may be used to control spacing in the final string (causes the resulting string to be pretty-printed). If it is a number, successive levels in the stringification will each be indented by this many space characters (up to 10). If it is a string, successive levels will indented by this string (or the first ten characters of it).

Returns: String

Sample

JSON.stringify({ uno: 1, dos : 2 }, null, '\t')

stringify(value, replacer)

Parameters

Object value The value to convert to a JSON string.
Array replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.

Returns: String

Sample

function censor(key, value) {
 if (typeof(value) == "string") {
   return undefined;
 }
 return value;
}

var foo = {foundation: "Mozilla", model: "box", week: 45, transport: "car", month: 7};
var jsonString = JSON.stringify(foo, censor);

stringify(value, replacer, space)

Parameters

Object value The value to convert to a JSON string.
Array replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.
Number space The space argument may be used to control spacing in the final string (causes the resulting string to be pretty-printed). If it is a number, successive levels in the stringification will each be indented by this many space characters (up to 10). If it is a string, successive levels will indented by this string (or the first ten characters of it).

Returns: String

Sample

JSON.stringify({ uno: 1, dos : 2 }, null, '\t')

stringify(value, replacer, space)

Parameters

Object value The value to convert to a JSON string.
Array replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.
String space The space argument may be used to control spacing in the final string (causes the resulting string to be pretty-printed). If it is a number, successive levels in the stringification will each be indented by this many space characters (up to 10). If it is a string, successive levels will indented by this string (or the first ten characters of it).

Returns: String

Sample

JSON.stringify({ uno: 1, dos : 2 }, null, '\t')

stringify(value, replacer)

Parameters

Object value The value to convert to a JSON string.
Array replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.

Returns: String

Sample

function censor(key, value) {
 if (typeof(value) == "string") {
   return undefined;
 }
 return value;
}

var foo = {foundation: "Mozilla", model: "box", week: 45, transport: "car", month: 7};
var jsonString = JSON.stringify(foo, censor);

stringify(value, replacer, space)

Parameters

Object value The value to convert to a JSON string.
Array replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.
Number space The space argument may be used to control spacing in the final string (causes the resulting string to be pretty-printed). If it is a number, successive levels in the stringification will each be indented by this many space characters (up to 10). If it is a string, successive levels will indented by this string (or the first ten characters of it).

Returns: String

Sample

JSON.stringify({ uno: 1, dos : 2 }, null, '\t')

stringify(value, replacer, space)

Parameters

Object value The value to convert to a JSON string.
Array replacer If a function, transforms values and properties encountered while stringifying; if an array (of String or Number), specifies the set of properties included in objects in the final string.
String space The space argument may be used to control spacing in the final string (causes the resulting string to be pretty-printed). If it is a number, successive levels in the stringification will each be indented by this many space characters (up to 10). If it is a string, successive levels will indented by this string (or the first ten characters of it).

Returns: String

Sample

JSON.stringify({ uno: 1, dos : 2 }, null, '\t')

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