Top jQuery Interview Questions and Answers [2023]

jQuery is a fast, lightweight, feature-rich JavaScript library included in a single .js file. It offers many built-in functions that enable web developers to accomplish various tasks easily and quickly. This article lists the top commonly asked jQuery Interview questions and answers for freshers and experienced candidates to help you crack your next interview.

jQuery is a popular JavaScript library that is used to simplify HTML document traversing, event handling, and animating for rapid web development. It helps frontend web developers in building interactive web pages. If you are preparing for a frontend developer job interview, then you must have a good knowledge of jQuery. In this blog, we have listed the top commonly asked jQuery Interview questions and answers to help you prepare for your interview. 

Top jQuery Interview Questions and Answers

Q1. What is jQuery?

Ans. jQuery is a fast, lightweight, feature-rich JavaScript library included in a single .js file. It offers many built-in functions that enable web developers to accomplish various tasks easily and quickly. jQuery is cross-platform and supports different types of browsers. It makes a website more interactive, attractive, and user-friendly. Before jQuery, JavaScript codes were lengthy and bigger, now jQuery helps developers by allowing them to write less and do more. 

Explore popular courses on Shiksha Online: 

Top Programming Courses	Popular JavaScript Courses
Popular Java Courses	Top Python Courses

Q2. What are the features of jQuery?

Ans. Below are some of the key features of jQuery:

1. Lightweight: jQuery is lightweight (around 19KB in size – minified and gzipped).
2. Simple and Easy: jQuery is easy to learn. It has predefined methods, allowing you to perform any task easily compare to JavaScript. 
3. Cross Browser Support:  It has cross-browser support and works well in IE, Safari, Chrome, and Opera.
4. DOM Manipulation:  It provides methods to manipulate DOM easily and efficiently. It is easy to traverse them and modify their content by using the selectors (Selecting DOM Objects)
5. Event Handling: It provides a great way to capture different events, like a user clicking on a link, without the need to clutter the HTML code itself. The event handler handles the event raised by the operation performed by the mouse, keyboard, and touch, etc.
6. AJAX Support: It offers several methods for AJAX functionality. It helps you develop a responsive and feature-rich website with AJAX technology. With its AJAX methods, you can request text, HTML, XML, or JSON from a remote server using both HTTP Get and HTTP Post.
7. Built-in Animations: jQuery comes with a variety of built-in animation effects which you can use on your websites. It has a predefined method “animate ()” to create custom animation on the webpage.

Check out the list of Top Universities Offering Free Online Programming Courses

Q3. What is the difference between JavaScript and jQuery?

Ans. The differences between JavaScript and jQuery are: 

JavaScript	jQuery
It is a high-level interpreted client-side scripting language.	jQuery is a lightweight JavaScript library.
JavaScript is an independent language.	jQuery uses resources given by JavaScript to make things easier.
It can be faster for DOM selection and manipulation compared to jQuery as JavaScript is directly processed by the browser.	It is also fast with modern browsers and modern computers. However, it has to be converted into JavaScript to make it run in a browser.
JavaScript is verbose and more time-consuming as the whole script is written.	Requires you to write fewer lines of code than JavaScript. One can import the library and use only specific functions or methods of the library in the code.
One may have to deal with cross-browser compatibility by writing extra code.	It is cross-browser compatible.

Also Read: Top JavaScript Interview Questions and Answers

Explore more about the difference between JavaScript and jQuery

Q4. List some methods used to provide effects?

Below are some effects methods:

Show()
Hide()
Toggle()
FadeIn() and
FadeOut()

Q 5. What is chaining in jQuery?

Chaining is a technique in jQuery that allows you to perform multiple operations on an element in a single line of code. It is possible because many jQuery methods return the elements they are called on, enabling you to call another method on the same set of elements.

Q6. Explain Selectors in jQuery. What are the different types of Selectors? 

Ans. jQuery Selectors are functions that are used to select and manipulate HTML elements. They use the expressions to find out matching elements from a DOM based on the given criteria (their id, classes, attributes, types, etc.). Once an element is selected, you can perform various operations on that element. jQuery selectors start with a dollar sign and parenthesis – $(). 

Below are some of the different types of Selectors: 

Selector	Description
element	Selects elements based on the element name
*	Selects all elements
#id	Finds an element with a specific id
.class	Finds elements with a specific class
:first	Selects the first element
:last	Selects the last element
:parent	Selects elements that are a parent of another element
:hidden	Selects hidden <p> elements

Explore the Top 8 Highest Paying IT Certifications

Q7. Differentiate between .empty() vs .remove() vs .detach() in jQuery.

Ans. .empty() vs .remove() vs .detach() are jQuery methods to remove elements from DOM. Below are the differences: 

.empty() – it removes all the child elements from matched elements.

Syntax:

$(selector).empty();

.remove() – it removes all the child elements of the matched element and the element itself. All events and jQuery data associated with the elements are also removed. 

Syntax:

$(selector).remove();

.detach() – It is the same as .remove() method, except that the .detach() method doesn’t remove jQuery data associated with the matched elements.

Syntax:

$(selector).detach();

Also explore: 

• Paid and free online courses by Coursera
• Popular online Udemy courses
• Top online edX courses

Q8. How to create, read, and delete cookies in jQuery?

Ans. We can use the jQuery cookie plugin to accomplish create, read, and delete cookie tasks in jQuery. 

Create cookie:

$.dough(“cookie_name”, “cookie_value”);

Read Cookie:

$.dough(“cookie_name”);

Delete cookie:

$.dough(“cookie_name”, “remove”);

Also Read: Java Interview Questions and Answers

Q9. What are the methods used to provide effects in jQuery?

Ans. jQuery effect methods enable us to create custom animation effects. The following are some effects methods used in jQuery:

Method	Description
animate()	Makes custom animation on the selected HTML elements
show()	Displays the selected elements
toggle()	Shows or hides the matched elements
stop()	Stops the currently running animation for the selected elements
fadeIn()	Fades in the selected elements
fadeOut()	Fades out the selected elements
fadeTo()	Fades in/out the selected elements to a given opacity
hide()	Hides the selected elements
fadeToggle()	Toggles between the fadeIn() and fadeOut() methods
stop()	Stops all the currently running animations

Must Read: Top Web Developer Interview Questions and Answers

Q10. Explain the difference between $(document).ready and $(window).load?

The $(document).ready event fires when the DOM is fully loaded and the page is ready for JavaScript and jQuery code to execute. On the other hand, the $(window).load event fires when all the elements on the page, including images, have been fully loaded.

Q11. How can you select an element in jQuery?

You can select elements in jQuery using CSS-style selectors, such as ‘$(‘#id’)’ for selecting an element by its id, ‘$(‘.class’)’ for selecting elements by their class, and ‘$(‘tag’)’ for selecting elements by their tag name.

Q12. What is a CDN? What are the advantages of using CDN?

Ans. jQuery CDN (Content Delivery Network) is a geographically distributed group of servers that work together to provide fast delivery of Internet content. A CDN provides the files from servers at a higher bandwidth, which leads to faster loading time. It is a method to include jQuery into a website without downloading and keeping it in its folder. There are many jQuery CDNs available in the market today, for example, jQuery’s CDN, Google CDN, and Microsoft CDN, etc.

Benefits of using CDN:

• Faster page loading 
• Saves bandwidth and reduces bandwidth costs
• Increases content availability and redundancy
• SEO Friendly

Explore popular Web Development Courses

Q13. How to add a jQuery library to the ASP.Net project?

Ans. We can add the jQuery library to the ASP.Net project by downloading the latest jQuery library from jQuery.com and including the references to the jQuery library file in the HTML/PHP/JSP/Aspx page.

For example: 

<script src=”_scripts/jQuery-1.2.6.js” type=”text/javascript”</script>

<script language=”javascript”>

$(document).ready(function() {

alert(‘test’);

});

Check out the 10 Best Software Development Tools and Frameworks to Learn

Q14. Explain the use of the toggle() method in jQuery.

Ans. The jQuery toggle() method shows the hidden elements and hides the shown element. This method toggles between the hide() and the show() method. 

• toggle() method runs show() when the element is hidden.
• toggle() method runs hide() when the element is visible.

Syntax:

$(selector).toggle(speed, easing, callback)

Parameters: 

• speed (optional): specifies the speed of the hide/show effect. Possible values – slow, fast, and milliseconds.
• easing (optional): specifies the speed of the element in different points of the animation. Possible values – swing (default), linear
• callback (optional): specifies the function to be called after completion of toggle() effect.

Q15. Explain the parameters used for the jQuery Ajax method.

Ans. Below are the four parameters used for the jQuery Ajax method:

1. URL – specify the URL to send the request
2. Type – specifies the type of requests (Get or Post)
3. Data – specifies the data to be sent to the server
4. Cache – decides whether the browser should cache the requested page

We hope these interview questions on jQuery will help you in preparing for your interviews. All the best!