jQuery Interview Questions and Answers: General and Expert Level

By Indeed Editorial Team

Updated 22 June 2022

Published 26 August 2020

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

Understanding some of the common jQuery interview questions can make you feel more confident in your job interview. The questions may vary depending upon the experience level and expertise required for the job. While basic jQuery knowledge may suffice for entry-level positions, you may be required to have an advanced level of understanding for senior-level jobs that use jQuery. In this article, we provide tips for preparing for a jQuery interview and list some of the general and advanced-level jQuery questions and answers you may encounter.

How To Prepare For jQuery Interview Questions?

jQuery is an advanced JavaScript framework used in high-level applications. Having a thorough understanding of the program shows employers you know the foundation of the language and how it applies to different environments. Here are some steps to help you prepare for jQuery interview:

  1. Understand the requirements of the job. Read the job description to gain a better understanding of the required skills. For example, if the position requires you to develop travel websites, you can refresh your knowledge on using jQuery to develop the functionalities and effects a travel website normally requires.

  2. Practise on your computer. Test your theoretical knowledge by creating different scenarios on your computer. For example, you may practice applying various animations to a web page or creating a contact form.

  3. Rehearse the interview. You can practise answering questions in front of a mirror. Alternatively, ask a friend to conduct a mock interview. They can give you feedback on your body language and other aspects to improve your performance.

General jQuery Interview Questions And Answers

General jQuery questions for IT job roles involve the basics of the framework. These questions are often seen in job roles requiring a basic understanding of HTML, CSS and website development. The following questions are common jQuery questions employers ask in job interviews:

  1. What is jQuery?

  2. Why do we use jQuery?

  3. What is a CDN?

  4. What is the minified version of jQuery?

  5. What are the advantages of jQuery.ajax?

  6. How can a jQuery enhance an application?

1. What is jQuery?

This is usually the first question asked in a jQuery-based interview. The interviewer wants to evaluate your basic understanding of jQuery. Keep the answer simple without getting too deep into technical details.

Example: “jQuery is an open-source JavaScript library used to simplify JavaScript programming. It is helpful in building high-level applications that require Ajax, event handling and CSS animation. jQuery is extremely lightweight and feature-rich. A large number of popular websites use jQuery.”

2. Why do we use jQuery?

jQuery simplifies and enhances the performance of JavaScript. You are required to know when and why programmers use jQuery instead of other frameworks. Try to explain the benefits of jQuery over other programs.

Example: “jQuery makes it easier to use JavaScript by allowing you to handle several applications simultaneously. It is highly useful in developing high-end web programs because it requires minimal coding. It also saves you time in designing websites. The websites designed using jQuery load faster than those built with other programs.”

3. What is a CDN?

A content delivery network speeds up the delivery of content by deploying multiple servers across different locations. Since jQuery files form a large part of the content that CDNs deliver, you may face this question in your jQuery interview. Explain how CDNs work and how they help in the improved delivery of content.

Example: “A CDN is a network of servers deployed across multiple locations for improved delivery of content. Web developers often host their jQuery library on CDNs. A CDN serves the cached version of the content from the nearest server to the client or from the server that has minimal load at the time of the request. If the user's web browser already has the jQuery downloaded from the CDN, it does not require downloading it again. This speeds up the loading of websites and also reduces server bandwidth.

4. What is the minified version of jQuery?

Many websites use a jQuery minified version to reduce page load time. Hence, most employers expect you to know about it. Answer this question by explaining how the minified version works and how it is different from regular jQuery.

Example: “The minified version of jQuery uses a jQuery.min.js file to significantly improve a website's efficiency. It lets a client download less data, which in turn reduces page load time and bandwidth consumption. I use minified versions of jQuery for large websites which may otherwise take a long time to load.”

5. What are the advantages of jQuery.ajax?

Using jQuery.ajax offers several advantages. Discuss your understanding of jQuery.ajax and how a project can benefit from using it.

Example: “Ajax uses JavaScript and XML to transfer data to and from a server. It works in the background without interfering with the display or behaviour of the web page. Thus, it increases the page speed and performance. Ajax provides cross-browser compatibility and is simple to use. It can load scripts, XML, HTML and JSON.”

Related: JavaScript Vs. Java: What Are The Fundamental Differences?

6. How can a jQuery enhance an application?

Discuss the various ways in which a company can use jQuery to improve an application. Giving specific examples lets the interviewer know that you have a clear understanding.

Example: “jQuery can enhance an application in a number of ways. For example, it allows you to combine scripts, incorporate search, handle events and control the style of elements using CSS. It offers support for Ajax and makes it possible to add animation and special effects on DOM elements. jQuery can also minify scripts to significantly reduce the size of coding without affecting the operational functions.”

jQuery Expert-Level Interview Questions

If you are an experienced candidate looking for a higher-level position, here are some advanced jQuery interview questions you can expect:

  1. What is a jQuery selector?

  2. How is jQuery.ajax() method different from jQuery.get() method?

  3. What is the difference between .attr() and .prop() methods?

  4. What are jQuery events?

  5. What are the jQuery effects?

  6. How can you increase jQuery performance?

1. What is a jQuery selector?

A jQuery selector lets you perform a search function. Explain the different types of selectors you use and how they are helpful in executing a search query.

Example: “A jQuery selector is a search function. It allows you to find matching HTML elements from a Document Object Model based on the given search criteria. You can use different types of jQuery selectors to search using different criteria. For example, an #ID selector searches for an element by ID, while a .class selector searches for a given class.”

2. How is jQuery.ajax() method different from jQuery.get() method?

Despite being similar, .ajax() serves a different purpose than the .get() method. Explain in what situations you would use one method instead of the other. Try to give specific instances to add clarity to your answer.

Example: “Both .ajax() and .get() are wrappers for .ajax(). In terms of usage, jQuery.ajax() is highly configurable and powerful. It is more suitable for handling an error because it lets you specify how you want to handle an error. You can also specify the amount of wait time for the command. On the other hand, the jQuery.get() method is more suitable for retrieving data. It allows you to inspect the code without making any changes.”

3. What is the difference between .attr() and .prop() methods?

Both of these methods are helpful in retrieving or setting the value of an element in the HTML tag. Explain how one differs from the other with the help of some examples.

Example: “The .prop() method retrieves the actual value of an element. The .attr() method provides additional information about the element by retrieving attributes. For example, tag, type, and ID are attributes. Property refers to the actual values for these attributes.”

4. What are jQuery events?

jQuery events bind a function to an event handler for a given element. Support your answer with some examples of common jQuery events.

Example: “jQuery events refer to the different actions of visitors. For example, checking a checkbox, clicking on a submit button and moving a mouse are all examples of jQuery events. jQuery events can be broadly categorised into keyboard, mouse, browser, form and document loading events. Some of the common jQuery events include click, double click, hover, mouse enter, mouse up and mouse down.”

5. What are the jQuery effects?

jQuery allows a web developer to give various effects to a web page. Specify some of the common effects jQuery programmers use in web designing.

Example: “jQuery effects refer to several techniques that the jQuery library provides for adding animation to a web page. For example, a .show() effect displays the selected elements, while a .hide() effect hides the elements on a web page. Some of the common effects I use quite often include toggle, fade in, fade out, finish, animate and clear queue.”

6. How can you increase jQuery performance?

There are various ways to optimise the performance of jQuery. Take the time to list some of your frequently used methods.

Example: “The very first rule of increasing jQuery performance is to use the latest version. You may link to a specific jQuery version instead of hard coding it. Combining and minifying scripts is another great way to boost jQuery performance. Use IDs instead of classes for the faster retrieval of an object using a browser's native method. Similarly, using cache instead of reusing your selectors enhances speed to a great extent.”

Related:
  • 15 Software Developer Skills and How To Develop Them
  • How Much Does A Java Developer Make? (With Job Roles
  • 15 Important Java Developer Skills (And How To Improve)

Please note that none of the companies mentioned in this article are affiliated with Indeed.

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