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
Examples
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
{name:"testObject",
id:10021,},
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);
</script>
JSON data objects are used to demonstrate the Linked Selection Javascript widget in a later section.
References