20+ AJAX Interview Questions for Web Development

AJAX Interview Questions for Web Development

AJAX Interview Questions

1. What is AJAX?

AJAX represents Asynchronous JavaScript and XML. It is a gathering of related innovations used to show information nonconcurrently. At the end of the day, it sends and recovers information without reloading the website page.

2. What are the advantages of AJAX?

Snappy Response
Transmission capacity use
The client isn't hindered until information is recovered from the server.
It enables us to send just vital information to the server.
It makes the application intuitive and quicker.

3. What are the disadvantages of AJAX?

  • Dependent on JavaScript
  • Security issues
  • Debugging is difficult

4. What are the real web applications of AJAX currently running in the market?

  • Twitter
  • Facebook
  • Gmail
  • Javatpoint
  • Youtube

5. What are the security issues with AJAX?

  • AJAX source code is lucid 
  • Assailants can embed the content into the framework

6. What are the technologies used by AJAX?

HTML/XHTML and CSS - These advancements are utilized for showing substance and style.
DOM - It is utilized for dynamic showcase and cooperation with information.
XML - It is utilized for conveying information to and from server
XMLHttpRequest - It is utilized for offbeat correspondence among customer and server.
JavaScript - It is utilized predominantly for customer side approval

7. What is the purpose of XMLHttpRequest?

  • It sends data in the background to the server.
  • It requests data from the server.
  • It receives data from the server.
  • It updates data without reloading the page.

8. What are the properties of XMLHttpRequest?

  • The essential properties of the XMLHttpRequest object are given underneath. 
  • onReadyStateChange - It is called at whatever point readystate quality changes. 
  • readyState - It speaks to the condition of the demand. 
  • responseText - It returns reaction as content. 
  • responseXML - It returns reaction as XML. 
  • status - It restores the status number of a demand. 
  • statusText - It restores the subtleties of status.

9. What are the important methods of XMLHttpRequest?

  • prematurely end() - It is utilized to drop the present demand. 
  • getAllResponseHeaders() - It restores the header subtleties. 
  • getResponseHeader() - It restores the particular header subtleties. 
  • open() - It is utilized to open the demand. 
  • send() - It is utilized to send the demand. 
  • setRequestHeader() - It includes ask for header.

10. What are the types of open() method used for XMLHttpRequest?

open(method, URL) - It opens the request specifying get or post method and URL.
open(method, URL, async) - It is same as above but specifies asynchronous or not.
open(method, URL, async, username, password) - It is same as above but specifies the username and password.

11. What are the types of send() method used for XMLHttpRequest?

  • send() - It sends get request
  • send(string) - It sends post request.

12. What is the role of the callback function in AJAX?

The callback work passes a capacity as a parameter to another capacity. In the event that we need to perform different AJAX assignments on a site, at that point we can make one capacity for executing XMLHttpRequest and a callback capacity to execute every AJAX errand.

13. What is JSON in AJAX?

JSON represents JavaScript Object Notation. In AJAX, it is utilized to trade information between a program and a server. It is straightforward, and information trade is quicker than XML. It underpins exhibit, object, string, number, and qualities.

14. What are the tools for debugging AJAX applications?

  • There are several tools for debugging AJAX applications.
  • Firebug for Mozilla Firefox
  • Fiddler for IE (Internet Explorer)
  • JavaScript HTML Debugger
  • MyEclipse AJAX Tools
  • Script Debugger

15. What are the different ready states of a request in AJAX?

There are 5 ready states of a request in AJAX.
  • 0 means UNOPENED
  • 1 means OPENED
  • 3 means LOADING
  • 4 means DONE

16. What are the common AJAX frameworks?

  • Dojo Toolkit
  • YUI
  • Google Web Toolkit (GWT)
  • Spry
  • MooTools
  • Prototype

17. How can you test the AJAX code?

JUnit is the open source unit testing system for customer side JavaScript. It is required to make experiments. The unit experiment is a code which guarantees that the program rationale functions not surprisingly.