Spry

About JSON

JSON stands for JavaScript Object Notation. It is a lightweight notation format that uses JavaScript syntax to provide a flexible, yet strict, method of storing and transmitting data. The language is flexible in that you can create and name the data structure in any way; it’s strict in that JSON follows a strict set of rules for its structure.

Following is an example of some basic JSON code:

{
    "firstName": "Jason",
    "lastName": "Jones",
    "address": {
        "city": "San Francisco, CA",
        "zip": 94121,
        "address": "444 Columbus Ave"
    },
    "email": [
        "jason@sf.com",
        "sjones@adobe.com"
       ]
}

The preceding code creates a JavaScript object that contains the data. A JavaScript object is a series of name and value pairs, written in a structured way. The basic structure of the object is as follows:

{name:value,name:value,name:value}

JSON data types

JSON supports a number of common data types. Each data type has a set of structural rules that you need to follow.

Data type

Description

Example

Boolean

In JavaScript, true and false are predefined keywords. To send a true value, send the word true.

{"active":true}

 

To send a false value, send the word false.

{"active":false}

String

In JSON, you must delimit strings by using double quotation marks. For a list of what characters are allowed and what characters must be delimited, consult the JSON web site.

{"address": "444 Columbus Ave"}

Number

Positive integers

{"zip": 94121}
 

Negative integers

{"total points": -123}

 

Floats

{"length":122.2344}
 

Scientific notation

{"atoms per mole":-6.023e+23}

Object

Objects are delimited by braces ({ }), and contain zero (0) or more property and value pairs, separated by commas. The example shows an object with two properties on it: "count" and "results". The "count" property has an integer value of 2, and the "results" value is an array.

{"count": 2, "results": [2, 3]}

Array

Arrays are delimited by square brackets ([ ]). Each item within the array is separated by a comma. Arrays can contain all supported JSON constructs. The example shows an array of five elements that includes Number, Boolean, String, Array, and Object data types.

{"values":[1, false, "test", [2, 3], {"test": 1}]}

Null

In JavaScript, null is a predefined object. To send a null value in JSON notation, use the word null. The word null must be lower-case to be valid.

{"email":null}