Web developer Interview Questions and Answers

It can be quite intimidating to appear in front of the person taking your interview, especially if you are not prepared. If you like to achieve success in the interview, it will be essential for you to get prepared for all the web developer interview questions typically asked. In this article, we will be mentioning the top 30 web developer interview questions and answers that you must not ignore by any means.

Web Developer Interview Questions

1. What is meant by Namespacing in JavaScript?

For this web developer interview question, it will not be a good idea to use global variables in JavaScript and other programming languages. Nevertheless, you might need to use these variables at times. Consequently, the idea of namespacing has been introduced by JavaScript that ties down a portion of the code plus registers it using a unique name.

The namespacing is a container name where we will hold functions, variables, and classes that we can repeat in other namespaces or namespaces with the identical name without involving any error.

2. How can page loading time be reduced?

In case you are going to appear in a typical web developer interview, then you ought to consider this question. In fact, page loading time can be reduced in the following ways:

• Reduce the size of the image.
• Make use of the most recent generation formats for graphics.
• Minify CSS, JavaScript, and HTML.
• Create AMPs (Accelerated Mobile Pages).
• Postpone the uploading of off-screen images.
• Get rid of useless widgets.
• Position script referencing at the bottom of external files and CSS at the top.
• Prevent multiple redirects.
• Minimize lookups.
• Reduce caching and redirects.
• Check the website’s present speed.
• Clean web code.
• Come across a decent hosting for hosting your site.

3. Why is HTTP 2.0 more beneficial than HTTP 1.1?

The most significant benefits of HTTP 2.0 over HTTP 1.1 are as follows:

• Loading speed is higher.
• Enhancement of web positioning.
• Less consumption of broadband.
• Automated prioritization.
• Immediate presentation.

4. What is meant by SVG, and what are its uses?

SVG is an abbreviation for Scalable Vector Graphics. It displays graphics that are vector-based. The graphical content rendered by it is based on an XML format. SVG helps to make the quality of the graphical content top-notch, thus offering the capability of furnishing top-quality graphics to the user.

5. How to differentiate IDs from Classes?

This is surely amongst the leading web developer interview questions that you ought to take into consideration. 

• IDs happen to be unique. On the other hand, classes aren’t unique.
• It is possible for each element to have just a single ID. The identical class can be used on more than one element.
• It is feasible for each page to have just a single element with that particular ID. Multiple classes can be used on the identical element.

6. What responsibilities do you have in your present company?

Since there has been a huge advancement in web development technology at present, this particular question bears special significance. On most occasions, the most typical responsibilities of a web developer are as follows:

• Creating user interface/website layout by employing standard CSS/HTML practices
• Writing testable, properly designed, and efficient code by using the most recent application development practices
• Accumulating and refining specifications according to the demands of the client
• Integrating information from various databases and back-end services
• Creating plus maintaining software documentation
• Staying plugged into innovative industry trends or technologies and applying them to activities and operations
• Maintaining, expanding and scaling the websites

7. What are the various pop-up box types available in JavaScript? 

If you are considering coding interview questions, then this one will be one of them. 3 types of pop-up boxes are available at present in JavaScript:

Alert – A message is being displayed with an OK button.

Prompt – A dialogue box is going to pop up requesting input from the user.

Confirm – A confirmation message window will pop up along with the OK plus the Cancel button.

8. Which one is used by you the most, JavaScript animations or CSS animations?

Both. JavaScript animation and CSS animation happen to be 2 main ways of creating animations for the web. Both of them can be used according to the requirements of the project.

CSS animations are effective in the following cases:

• When transitions are not complicated. For instance, toggling inside the element states.
• When the UI elements happen to be self-contained. For example, depicting a tooltip.

JavaScript animations are effective in the following cases:

• When we expect advanced animations within the project, such as bouncing.
• When we need a superior control level.
• While making drawings in HTML canvas.

9. What are the web development tools used by you?

While answering this web developer interview question, you will come across several web development tools at present, some of which we have mentioned below:

• CodeKit for minifying, combining, and syntax-checking in JavaScript.
• GitHub for working together on a specific project with a team.
• JS for structuring the web app plus creating a 1-page application.
• Grunt to automate tasks that are repetitive.
• CodePen for deploying a website and creating test cases.

10. How does HTML differ from XHTML?

Both HTML, as well as XHTML is reputed for writing web pages. However, HTML has been extended from SGML tagging, while XHTML happens to be an app of XML (Extensible Markup Language).

HTML comes with 3 components – start tag plus end tag, properties of the element inside the tag, and content as both graphics and text. On the other hand, XHTML consists of just one root element that consists of lower case elements, and the assigned value ought to be closed and should be encircled by quotation marks. As a matter of fact, XHTML happens to be more expressive, unlike HTML.

11. How will you take care of a client who is not satisfied with the web delivery of your team?

This is one of the top web developer interview questions that you ought to be aware of. The customer is considered to be the king for every company, and none likes to lose his client by any means. Consequently, you should be prepared for this question while appearing for the interview. 

It will be a good idea to begin by narrating any earlier incident related to handling clients. Define the problems faced by the client, and also specify the solution which you did for helping the client. This will inform the interviewer that you will handle an unhappy client in the best possible way.

12. What is meant by HTTP/3?

This one is the innovative 3rd-generation HTTP standard that was introduced in 2019. It is reputed for its innovative standards, reliable, fast, and secure connection. A faster web experience is assured by HTTP/3 since it makes use of QUIC. Brands such as Facebook and Google are employing QUIC right now, thanks to its ability to accelerate the web very fast.

13. What is implied by ETag, and how does it work?

An ETag or an entity-tag is an HTTP header used for conditional requests from web browsers and web cache validation. A web server allocates it to a particular version of a resource existing at a URL. Once the ETag is read by the server from the client request, it will be capable of telling whether to inform the client to use the local copy or send the file. 

14. What exactly is Webpack?

Webpack is referred to as a static module bundler intended for JavaScript. This build tool is employed for bundling JavaScript files to be used in a browser. Webpack puts bundles of assets like images, codes, files, and fonts within a dependency graph and allows you to make use of require() in the source code for pointing to local files such as images. Although a web pack might be slowing you down initially, it will provide you with fantastic speed advantages if used properly.

15. What is meant by DOM?

The DOM (Document Object Model) happens to be a programming interface representing XML and HTML documents as objects and nodes. Put simply; it defines the documents’ logical structure and the manner in which the documents are manipulated. DOM allows the developers to create, alter, and also delete the structure of the document, including content and style.

When a document is displayed on the browser, its content should be shared with its style data. HTML and CSS are converted by the browser into the DOM, which combines the content of the document along with its style.

16. How can you differentiate between adaptive design and responsive design?

The responsive design sticks to the notion of flexibility. Adapting to the screen’s size provides a fantastic viewing experience of a site irrespective of what sort of device is employed to see it. Responsive websites use flexible grids and CSS media queries to alter styles depending on various aspects of the device, like width, height, and display type.

Adaptive design makes use of static designs rather than flexible layouts. The design is based on breakpoints that don’t make any response after they are loaded initially. After detecting the sort of device used along with its other features, it provides the layout and feature according to a set of characteristics that have been predefined.

Both adaptive, as well as responsive designs help in optimizing user experience across various target devices. Both of them adjust for different resolutions, control mechanisms, and viewport sizes.

17. What is implied by progressive rendering in HTML?

Progressive Server Side Rendering or Progressive Rendering happens to be an approach that helps you update small portions of the webpage sequentially, and it can be streamed to the client in parts while there is no need to wait for the entire page to be rendered.

It implies that it will be feasible to stream the content on the server after beginning to render it to the client, and there is no need to wait for the rendering of the non-critical element. It is capable of bridging the advantages of CSR as well as SSR.

18. What exactly are CSS selectors?

CSS selectors are a portion of a CSS rule set. CSS selectors will enable you to “find” HTML elements that you would like to style. The HTML elements are selected as per their class, id, attribute, type, etc.

The different types of CSS selectors are as follows:

• Id Selector
• Attribute selectors
• Element Selector
• Class Selector
• Pseudo-Elements
• Combinator
• Universal Selector
• Pseudo-Classes 

19. What are some innovative features which have been introduced in CSS3?

Lots of changes have been brought about by CSS3, making the entire framework more powerful and user-friendly. Some innovative features have been added, and these are as follows:

• Rounded corners
• Custom layout
• Media queries
• Animation

20. How to differentiate between SVG and Canvas?

This one is undoubtedly one of the most critical web developer interview questions that you simply cannot ignore. 

• While Canvas is dependent on resolution, SVG is resolution-independent.
• Event handlers are not supported by Canvas. However, SVG is known to support event handlers.
• Canvas is ideal for small-scale rendering apps. SVG is more suitable for rendering applications that are large-scale.

21. How is Webkit used in CSS3?

Webkit happens to be a vital software component of CSS that enables the easy rendering of CSS and HTML elements in different browsers like Chrome, Safari, and Firefox.

There are quite a few browser engines like:

• Presto for Opera
• Gecko for Mozilla
• Edge for Internet Explorer

22. What do you mean by HTML5 Web Storage?

For this web developer interview question, you could say that web apps can use HTML5 Web Storage to store data locally within the user’s browser. The data will be stored in name/value pairs; only data stored on its own can be accessed by a web page. 

Put simply; web storage enables the storing of massive amounts of data locally. It is not going to impact your web app’s performance.

2 types of web storage are available for storing data locally:

• Session storage – Data is stored for a single session only. Once the user’s browser is closed, the data will be removed from the browser, and the entire session will be lost.
• Local storage – It stores data without any expiration date. After it is stored, the data will be present in the local storage even though the user’s browser might be closed.

23. What exactly is long polling?

Long polling allows you to have a persistent link with the server. The client is going to poll the server in long polling while asking for new info. A client’s connection is held open by the server for a considerable span of time. This connection will be closed once a connection timeout takes place or the data is returned to the client.

Long polling flow:

• The server will receive a request.
• The server is accountable for holding the connection of a client until fresh data is obtainable.
• The server makes a response to the request after the arrival of the new information.
• One more request is sent by the browser immediately.

24. What are the advantages of DTD?

Document Type Declaration or DTD is responsible for defining an XML document’s structure. It is possible to declare it as an external source or within an XML document.

• Internal Declaration of DTD – When a DTD is going to be declared inside the file
• External Declaration of DTD – When a DTD is going to be declared within a separate file

DTD advantages

• You can use it for defining your format for XML files allowing developers and users to comprehend the data’s structure.
• Validating parsers are provided by it along with a map of validating the XML document.

25. What are the properties of CSS transitions?

This is one of the most intriguing JavaScript interview questions out there. CSS3 transitions allow the element to change slowly and smoothly from one particular state to another. It is quite simple to use, and they offer remarkable animation effects. The main properties which will be needed in transition are as follows:

• transition-property
• transition-delay
• transition-timing-function
• transition-duration

Conclusion

The above-mentioned web developer interview questions should allow you to comprehend what type of questions you can expect at the interviews. However, it will be a sensible idea to join a certification course if you would like to gain expert-level skills to clear the interviews in any company of your liking. 

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