JSON is a lightweight data-interchange format that is easy for humans to read and write and for machines to parse and generate. It is built on two structures: a collection of name/value pairs and an ordered list of values. JSON is text-based and language independent, yet closely resembles JavaScript object syntax. It is used primarily to transmit data between a server and web application, serving as an alternative to XML. Compared to XML, JSON is simpler, faster and easier to use.

1. JSON (JavaScript Object Notation)
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2. What is JSON?
 Light weight data-interchange format.
 Subset of JavaScript.
 Language independent.
 Text based.
 Easy to parse .
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3. Why JSON?
JSON is recognized natively by JavaScript. No need for parsing an
XML document to extract the data.
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4. JSON is Not…
 JSON is not a document format.
 JSON is not a markup language.
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5. Properties of JSON
 Human and machine readable format.
 No support for Unicode.
 Self-documenting format that describes structure and field names.
 Strict syntax and parsing requirements.
 Represents the most general computer science data structures like
records, lists and trees.
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6. Where can JSON be used?
 Can be used for transferring medium amounts of data.
 Used in Java Script and then rendered on HTML pages.
 AJAX has many applications for JSON.
 Use JSON for applications that are browser based.
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7. JSON Data Types
 Strings -Control Characters
 Number-Integer, Real and Floating
 Boolean-True and False
 Null
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8. JSON Data Types (Cont…)
String
Strings must be delimited by the double quote characters.
Example: ”Address”, "444 Colombia"
Boolean
In JSON “True" and “False" are pre-defined keywords.
Example: “Active":True
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9. Data types (Cont…)
Number
JSON includes positive integers and Negative integers.
Example: “Total points” -123
Null
Null string, also known as an empty string, is a string of zero length.
Example: “Email":null
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10. Simple Example of a JSON File
{ "menu": "File",
"commands": [ { "title": "New“, "action":"CreateDoc” },
{ "title": "Open", "action": "OpenDoc” },
{ "title": "Close“, "action": "CloseDoc” } ] }
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11. JSON Object
JSON Object Notation
 JSON object is an unordered set of name/value pairs and ordered
list of values.
 Object begins with { (left brace) and ends with } (right brace).
 Each name is followed by (colon).
 Name/value pairs are separated by , (comma).
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12. JSON Representation of an Object
Var HomeAddress =
{
"Address" : “Srini",
"City" : “Bangalore",
"PostalCode" : 580006
};
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13. JSON Functions
 JSON_decode — Decodes a JSON string.
 JSON_encode — Returns the JSON representation of a value.
 JSON_last_error — Returns the last error occurred.
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14. JSON Decode
Decode parses the strings as a JSON-syntax string and returns the
generic JSON object representation.
json_decode()
mixed json_decode ( string $json , bool $assoc)
Takes a JSON encoded string and converts it into a PHP value.
$json
The JSON string being decoded
$assoc
False ----Return the value as an object
True ----Return the value as an associative array
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15. JSON Decode Example
<?php
$json = '{"foo-bar": 12345}';
$obj = json_decode($json);
print $obj->{'foo-bar'}; // 12345
?>
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16. JSON Encode
JSON encode returns the JSON representation of a value.
string json_encode ( mixed $value )
Returns a string containing the JSON representation of $value.
$value
 Value being encoded, Can be any type except a resource.
 Function only works with UTF-8 encoded data.
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17. JSON Encode Example
<?php
$arr = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);
echo json_encode($arr);
// Output {"a":1,"b":2,"c":3,"d":4,"e":5}
$arr = array ( 1, 2, 3, 4, 5 );
echo json_encode($arr);
// Output [1,2,3,4,5]
$arr['x'] = 10;
echo json_encode($arr);
// Output {"0":1,"1":2,"2":3,"3":4,"4":5,"x":10}
echo json_encode(54321);
// Output 54321
?>
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18. JSON in JavaScript
JavaScript Object Notation is a lightweight data-interchange
format that is completely language independent text format
which is fast and easy to understand.
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19. Example - JSON in JavaScript
<html>
<head>
<title>
Object creation in JSON in JavaScript
</title>
<script language="javascript" >
var JSONObject =
{
"name" : "Amit“,
“address" : "Bangalore“,
"age" : 23,
"phone" : "4565763",
“MobileNo" : 981100092
};
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20. Example - JSON in JavaScript (Cont…)
document.write("<h2><font color='skyblue'>Name</font>::“
+JSONObject.name+"</h2>");
document.write("<h2><font color='skyblue'>Address</font>::“
+JSONObject.address+"</h2>");
document.write("<h2><font color='skyblue'>Age</font>::“
+JSONObject.age+"</h2>");
document.write("<h2><font color='skyblue'>Phone No.</font>::“
+JSONObject.phone+"</h2>");
document.write("<h2><font color='skyblue'>Mobile No.</font>::“
+JSONObject.MobileNo+"</h2>");
</script>
</head>
<body bgcolor="#cc4488">
<h3>Example of object creation in JSON in JavaScript</h3>
</body>
</html>
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21. AJAX with JSON
Both XML and JSON use structured approaches to mark up data.
 More and more web services are supporting JSON.
Example
Yahoo's various search services, travel planners, and highway
traffic services.
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22. Why JSON is Better than Ajax?
JSON is widely used in AJAX. The X in AJAX stands for XML.
Example
{
"fullname": "Swati Kumar“, "org": "Columbia",
}
<?xml version='1.0‘ encoding='UTF-8'?>
<element>
<fullname>Swati Kumar</fullname>
<org>Columbia</org>
</element>
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23. JSON and XML
Benefits of JSON
 The easiness of reading
The easiness of using
Benefits of XML
XML is extensible.
Widely used and recognized by almost all programming languages.
Unfortunally, both XML and JSON are enable to integrate a large
amount of data in binary form.
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24. Example
{
"firstName": “Sahana",
"lastName": "Saniya",
"age": 25,
"address": {
"streetAddress": “2nd Street",
"city": “Bangalore",
"state": “India",
},
"phoneNumber": [
{ "type": "home", "number": “234243" },
{ "type": "fax", "number": “645654" }
],
"newSubscription": false,
"companyName": null
}
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25. Equivalent for the above in XML could be
<Person>
<firstName>John</firstName>
<lastName>Smith</lastName>
<age>25</age>
<address>
<streetAddress>21 2nd Street</streetAddress>
<city>New York</city>
<state>NY</state>
<postalCode>10021</postalCode>
</address>
<phoneNumber type="home">212 555-1234</phoneNumber>
<phoneNumber type="fax">646 555-4567</phoneNumber>
<newSubscription>false</newSubscription>
<companyName />
</Person>
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26. JSON is Like XML because…
 Both are self-describing and thus human readable.
 Both are hierarchical (i.e. we can have values within values.)
 Both can be parsed and used by lots of programming languages.
 Both can be passed around using AJAX (i.e. httpWebRequest).
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27. JSON Vs XML
 JSON stands for JavaScript Object Notation, Considered as the
subset of JavaScript.
 XML on the other hand is a mark-up language that could be used in
different languages.
 Parsing JSON encoded data is much faster than parsing XML
encoded data.
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28. JSON Vs XML (Cont…)
XML
<result>
<people>
<person firstName=“Aman" lastName=“Valya"/>
<person firstName=“Suman" lastName=“Valya"/>
...
</people>
</result>
JSON
{
people:
[
{ 'firstName': ‘Aman', 'lastName', ‘Valya' },
{ 'firstName': ‘Suman', 'lastName', ‘Valya' },
...
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29. Why Use JSON Over XML?
 Lighter and faster than XML as on-the-wire data.
 JSON objects are typed while XML data is type less.
 JSON types are string, number, array, Boolean.
 XML data are all string.
 Data is readily accessible as JSON objects in your JavaScript Code.
 XML data needed to be parsed and assigned to variables through
tedious DOM APIs.
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30. Features of JSON
 Provides multiple functionalities such as encode, decode/parse.
 Flexible, simple and easy to use.
 Supports streaming output of JSON text.
 Heap based parser.
 High performance.
 No dependency on external libraries.
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31. JSON Data Interchange
 JSON is a simple, common representation of data.
 Communication between servers and browser clients.
 Communication between peers.
 Language independent data interchange.
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32. Thank you
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