Top 20 JQuery Interview Questions and Answers

One of the most popular libraries of JavaScript is jQuery. It is a tiny library for web development that provides an exciting web experience. In this article, wewe have collected a set of frequently asked jquery interview questions to get you familiar with the interviews' topics. If you are looking to learn JavaScript, read about its learning path here.

Basic JQuery Interview Questions

Here are some basic jquery interview questions:

1. Why is jQuery known as a feature-rich library?

This is because jQuery has several features such as easy DOM manipulation, event handling, built-in animations, cross-browser compatibility, supports CSS3, and is lightweight. 

2. In what scenarios jQuery can be used?

jQuery is used mainly to add animation effects, call functions on events, apply dynamic or static CSS, and manipulate purposes. 

3. Can you select all elements using jQuery? How?

Yes, all elements can be selected using jQuery using $('*') available in a DOM.

4. What are different selectors in jQuery used for?

There following selectors in jQuery is used as:

$('div') is used for selection all div tags in the document, $('#TextId') is used for selecting elements whose ID is TextId and $('.myclass') is used for selecting all elements whose class is .myclass.

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5. What is the purpose of jQuery AJAX?

AJAX stands for Asynchronous JavaScript and XML. It helps in loading and exchanging data without a browser page refresh and only via server. jQuery provides a rich set of AJAX methods to develop web applications.

6. How to deal with cookies in jQuery?

Dough cookie plugin can be used to deal with cookies in jQuery. It has powerful features and is easy to use. For example: $.dough(“cookie_name”, “cookie_value”);

can be used to create a cookie.

7. Popularly asked jQuery interview questions are how to get the text contents and set the text contents of an element using jQuery?

Text () method is used to get combined text contents of all matched elements, and text(Val) is used to set those text contents. 

8. How is css(‘width’) different from width() in jQuery?

These two are different methods available in jQuery to change the width of an element. The difference is that in CSS('width'), we have to add px in the width value while this is not required in width().

9. Does Bootstrap require jQuery?

jQuery is used for JavaScript plugins by Bootstrap. However, if we use the CSS part of Bootstrap, jQuery is not needed.

10. How can you include jQuery on a page?

jQuery can be included in a page inside the script tag, remote copy of Ajax API and jQuery.com, embedder script using client script object and a local copy of script manager control.

Advanced JQuery Interview Questions

Next up, let us have a look at advanced jquery interview questions!

1. Why are Ajax methods preferred in jQuery?

jQuery Ajax methods are simple, offer cross-browser support, send GET and POST requests and load XML, JSON, Scripts or HTML.

2. How is parent() method in jQuery different from parents() method?

The parent() function travels only a single level in the DOM tree, whereas parents() searches through the entire DOM tree. 

3. What is jquery.min.js?

It is a compressed version of jquery.js as shorter variable names are used to preserve bandwidth. It functions precisely similar to jquery.js. The compressed version is used to increase the efficiency of web pages. 

4. What is a content distribution network?

A content distribution network or CDN is an extensive distributed system of servers deployed across the Internet. Its primary objective is to offer highly available as well as high-performance content to end-users. 

5. Ajax functions are generally asked as a part of jQuery interview questions. List some of them.

  1. .ajaxStop()- when all requests are complete, this registers the handler to be called.
  2. .ajaxStart()- when the first Ajax request begins, this registers the handler to be called.
  3. .ajaxSuccess()- when an ajax request is completed, this registers the handler to be called. 

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6. If you want to check if an element is empty or not, which methods can be used?

We can use the '.empt' selector or '$.trim()' function to check if an element is empty. 

7. How is 'this' different from '$(this)' in jQuery?

We use $(this) to use jQuery methods, which refers to the DOM element. 

8. What is a prop() in jQuery? How is it different from Attr()?

The prop() method is used to obtain the value of the first element property, and Attr() is used to extract the value of the first element's attribute.

9. What is the advantage of method chaining in jQuery?

Multiple jQuery commands on a particular element can be executed in one go with chaining. It helps in implementing various actions on an element rather than one after the other.

10. Tell something about the finish method in jQuery.

The .finish() method stops all queued animations and place all the elements in their final state.

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Conclusion

With this, we come to the end of jquery Interview questions. jQuery finds its application in web development, and if you are looking to make a career in it, you must enroll in Simplilearn’s Full-stack web developer course. Get certified and make your profile stand out in the coming jquery interviews! Start now!

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