Way 2 Web

Web development tips


JSON - Javascript Object Notation, is a data format used to describe Javascript data types.

You'll see it used to describe Javascript objects.

It is a very useful way of building Javascript data objects and, since in theory it is language-independent, it may be used for data interchange as well.

The basics

Curly brackets enclose an object
Square brackets enclose an array
Colon delimits an element's name and value
Comma delimits elements


1. An array of objects

[{name:"elem1", value:21},
 {name:"elem2", value:"testing 1 2 3"},
 {name:"elem3", value:null}]

2. An object, one of the elements being an array

 colors: ["blue", "green", "red"]

3. Javascript, data object

A data object is defined and then used programmatically.

<script language="javascript">
    var data = {name:"testObject", id:10021, 
                colors:["blue", "green", "red"]};
    alert('This ID is:' + data.id);
    alert('Number of colors:' + data.colors.length);

JSON data objects are used to demonstrate the Linked Selection Javascript widget in a later section.