Top 30 Ajax Interview Questions

Every big company wants to satisfy user’s requirement. Every user wants easy navigation, interactive environment, Dynamic, Compact technology. Knowledge of AJAX is mandatory for every developer to develop interactive applications. Coding Tag provides you Top 30 questions with every basic concept of AJAX selected from different JQUERY AJAX and JavaScript tutorials and assists you to crack a developer interview.

1) Name the technologies AJAX comprises of?

Javascript, XML, CSS, JSON, PHP, DOM and <html>

HTML and CSS are used as Client Side.

JavaScript is used to send a request.

XML act as request formats and PHP is used for the server side.

2) AJAX?

Ajax Stand for Asynchronous JavaScript and XML. It is not a programming language, is a technology that plays an integral role for any developer to develop any dynamic websites. AJAX acts as a background process of Transacting data from the Server. You can request multiple requests Simultaneously. When we want to update Specific page of Website instead of refreshing whole page AJAX technology can be used. Example of this technology can be all All Social media, YouTube, GMail.

3) List some live examples of AJAX?

Following are AJAX examples:

Google Search: When we try to search in live search engine, the suggested words are due to the Ajax Technology.

Facebook: Facebook is also the best example of AJAX technology, when we write any post, the only post is updated instead of the whole page. Live chat, comments features of Facebook work on this AJAX Technology.

YouTube Search Engine.

Google Map.

4) Features of AJAX?

  • Interactive Web Applications
  • Fast Performance
  • Less Bandwidth Requirement
  • Faster Websites
  • Decrease Response Delay
  • Multiple Requests to the web server
  • Reload specific partInt
  • Less Network Load
  • DataView Control

5) How can concurrent AJAX requests be handled?

JavaScript closures are used to handle such synchronous requests. Firstly functions are built and then parameters (back function and URL) to corresponding functions are selected with the use of Closures and pass to AJAX URL Objects.

6) Which function can be used to revoke the XMLHttpRequest in AJAX?


7) Which object is used in AJAX requests or server Interactions?


8) Are there any restrictions on usage of no of update panels per page ?


9) Write a syntax to create AJAX objects?

var v = new AjaxObject(“object containing path”);

10) Name a function passed as a parameter to another function in AJAX?

Callback Function

11) What are the essential methods used in XMLHttpRequest?

  • open()
  • send()
  • setRequestHeader()

12) Is AJAX Supports Nested Update Panel?


13) Explain Working of AJAX?

When an event takes place when the page is loaded. JavaScript creates an XMLHttpRequest object to send a request to Server. The server takes action on that process and sends back a response. JavaScript read that response and perform page update.

14) What are the functions of GET and POST in AJAX?

POST requests are more secure, robust and can be deal with sensitive data. You can’t bookmark post requests. Post requests don’t hold cache and you can transmit an unlimited amount of data.

GET requests are less secure and can’t deal with sensitive data. You can bookmark GET requests and hold cache. You can’t transmit unlimited data, there are restrictions in length.

15) Name some Browsers that AJAX?

  • Netscape version 7.1 and above.
  • Mozilla Firefox 1.0 and above.
  • Apple Safari 1.2 and above.
  • Konqueror.
  • Microsoft Internet Explorer 5 and above.

16) Every Browser support AJAX?

The Browsers that do not support JavaScript object creation i.e. XMLHttpRequest, does not support AJAX.

17) How can AJAX be used in interactive Communication?

AJAX can be used with an XML file.

18) How can you select a client from a dropdown list in AJAX?

showCustomer() can be triggered by “onchange” event.

19) List some controls used in AJAX?






20) Name the DLL containing Ajax Control Toolbox?

AjaxControlToolKit.dll located in the project Bin folder.

21) UpdatePanel in AJAX?

UpdatePanel is the most powerful control used in AJAX used to update some portion of the website. If you write the code on the label that you are inside UpdatePanel, instead of the entire page, only content on the inside update panel goes to the server.

22) Name the elements of AJAX architecture?

There are two elements of AJAX architecture i.e. AJAX client and AJAX server architecture.

23) Is JavaScript Knowledge is mandatory in AJAX?

Yes, if we want to add AJAX functionality to our website, JavaScript knowledge is necessary.

24) How can we extend the functionalities of ASP.NET controls in AJAX?

AJAX Control extender toolbox with a block of Javascript code can be used to extend various functionalities.

25) Name the Triggers used in UpdatePanel?

PostBack Trigger and AsyncPostBack Trigger are the two triggers used in UpdatePanel.

26) Methods used for Cross Domain AJAX calls?

Two methods JSONP and CROS are used.

27) What are proxied and proxyless calls used in AJAX?

Proxyless CallsProxied Calls
Proxyless calls are made through the use of utility JavaScript functions i.e.
HTML_AJAX.replace() or
These are used to copy PHP classes on the JavaScript side. These are made by use of stub objects.

28) AJAX polling?                                                    

In AJAX, the activity of routinely retrieving data from web server to attain near-live data is called as AJAX polling.

29) What is long polling in AJAX?

In long polling, connection is not expired until the response is sent. Long Polling is extended form of normal polling.

30) Ready states in AJAX?

0 = uninitialized
1 = server connection established
2 = request received or loaded
3 = request is processing
4 = request Completed and response is ready


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