Syntax of JSON

JSON with Ajax

Basically Syntax of JSON is the subset of the JavaScript syntax.

It has following notation:

  • Data is represented in name/value pairs.
  • The name/value pairs are separated by , (comma).
  • Curly braces hold objects.
  • Square brackets hold arrays.

Below is a example of Syntax of JSON:

 {"Name":"Tim", "Age":"25"},
 {"Name":"John", "Age":"30"},
 {"Name":"Jane", "Age":"45"}

students[0].Name + “:” + Name[0].Age;

will be Tim:25

The following datatypes are supported by JSON:
Number, String, Boolean, Array, Object, Whitespace, null

Read Also: Json JSON with Ajax

JSON reads data from a web server, and display in a web page.

var text = ‘{“students”:[
{“Name”:”Tim”, “Age”:”25″},
{“Name”:”John”, “Age”:”30″},
{“Name”:”Jane”, “Age”:”45″}

Object From String:
JSON.parse(text) can be used to convert a JSON string into a JavaScript object:
var obj = JSON.parse(text);

Using eval():
You can use eval() function to convert a JSON string into a JavaScript object:
var obj = eval (“(” + text + “)”);

JSON is not a document format and this is not a markup language. Even, this is not a general serialization format in that it does not have a direct representation for cyclical structures, although it can support a meta representation that does.

JSON is not extensible and it does not need to be. It can represent any non-recurrent data structure as it is. JSON is a flexible as new fields can be added to existing structures without obsoleting existing programs.
In this sense, XML is also not extensible. This is possible to add new tags and attributes, but this is not possible to extend XML to add expressive syntax for arrays and objects and numbers and booleans.

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