Ajax interview questions and answers Latest

AJAX Tips & Tricks

Ajax interview questions and answers

Question :: What is an UpdatePanel Control?

View Answer

An UpdatePanel control is a holder for server side controls that need to be partial postbacked in an ajax cycle. All controls residing inside the UpdatePanel will be partial postbacked. Below is a small example of using an UpdatePanel.

As you see here after running the snippet above, there wont be a full postback exhibited by the web page. Upon clicking the button, the postback shall be partial. This means that contents outside the UpdatePanel wont be posted back to the web server. Only the contents within the UpdatePanel are refreshed.

Explain about the multimedia functions of ajax?

View Answer

Ajax lacks built in multimedia functions. It is not so supportive of inbuilt applications but uses other browser functionalities and plugin`s such as SVG, Quicktime and flash pugin. General multimedia for ajax is achieved through mashup and hack. These multimedia functions can be obtained from outside which helps in building excellent applications.

Are Ajax applications easier to develop than traditional web applications?

View Answer

What are limitations of Ajax?

View Answer

An Ajax Web Application tends to confused end users if the network bandwidth is slow, because there is no full postback running. However, this confusion may be eliminated by using an UpdateProgress control in tandem.

An Ajax Web Application is little bit confused to end users because if there is huge amout of data to show in grid like structure than it may not be worked that why we were put a progress bar to know the end user that there is something going on.

Question :: What is Dojo?

View Answer

Question :: Can Ajax be implemented in browsers that do not support the XmlHttpRequest object?

View Answer

How do I handle concurrent AJAX requests?

View Answer

Question :: How to make sure that contents of an UpdatePanel update only when a partial postback takes place (and not on a full postback)?

View Answer

Should I use XML or text, JavaScript, or HTML as a return type?

View Answer

Are there any security issues with AJAX?

View Answer

What browsers support AJAX?

View Answer

How do I send an image using AJAX?

View Answer

Can AJAX technology work on web servers other than IIS?

View Answer

Explain about web analytics problem with Java?

View Answer

How do I get the XMLHttpRequest object?

View Answer

Question :: How to handle multiple or concurrent requests in Ajax?

View Answer

Should I use an HTTP GET or POST for my AJAX calls?

View Answer

When do I use a synchronous versus a asynchronous request?

View Answer

Not totally. Most browsers offer a native XMLHttpRequest JavaScript object, while another one (Internet Explorer) require you to get it as an ActiveX object....

Question :: Is AJAX code cross browser compatible?

View Answer

How do I test my AJAX code?

View Answer

How do we abort the current XMLHttpRequest in AJAX?

View Answer

What is the XMLHttpRequest object?

View Answer

It offers a non-blocking way for JavaScript to communicate back to the web server to update only part of the web page.

How do I create a thread to do AJAX polling?

View Answer

JavaScript does not have threads. JavaScript functions are called when an event happens in a page such as the page is loaded, a mouse click, or a form element gains focus. You can create a timer using the setTimeout which takes a function name and time in milliseconds as arguments. You can then loop by calling the same function as can be seen in the JavaScript example below.

What is DOJO?

View Answer

Dojo is a third-party javascript toolkit for creating rich featured applications. Dojo is an Open Source DHTML toolkit written in JavaScript. It builds on several contributed code bases (nWidgets, Burstlib, f(m)), which is why we refer to it sometimes as a "unified" toolkit. Dojo aims to solve some long-standing historical problems with DHTML which prevented mass adoption of dynamic web application development.