30 Essential JavaScript Interview Questions for Freshers

JavaScript is considered one of the best languages for beginners to learn programming. Mostly because it is vastly applied for web development, and also due to the fact that language features let even flawed code run. It is not too restrictive like other languages: it permits omission of certain semicolons and takes care of the memory management for you.

The programming industry is interesting yet complicated. Similarly, passing an interview can be as easy as walking through an open door or it can get challenging to try and solve particularly tricky tasks. Taking the chance is the only option here – otherwise you’ll never guess.

At the same time, we can help to prepare for the interview to be sure you have covered all the essential topics. Yes, you may be asked rather weird questions, but once you are prepared, you can be certain that you answer at least the technical ones correctly.

Here we have listed thirty questions that you better prepare answers to before you enter the interview for the position of a JavaScript developer.

Common Introductory Questions

The interviewer normally inquires about these points to get to know you better, to observe your instant reactions, see how you think, and look at how you might fit into the company’s team.

The answers to these questions should be relatively short, since they do not have much weight in the bigger picture.

Remember that there is no need to hurry and give answer right away: you are free to take pauses to think about the question deeply. In theory, these questions are designed to open you up a little, let the interviewer to see your true essence.

1. Why do you like programming? Do you have a particular interest in this process?
2. What did you master yesterday (this week)?
3. Tell us about your preferred development environment. What operating system, IDE, terminal do you use? Why did you select them?
4. If you could only learn one technology this year, what would it be? How exactly would you work on acquiring this skill?
5. What resources and tools do you stick with, are there any forums you visit to learn about the latest frontend development and design trends? Do you have any favorites among all of the resources you turn to?
6. If you become a member of a project where the team uses tabs, while you prefer spaces, what will you do? Will you attempt to persuade the team to switch to spaces, or will you join the general practice and use tabs?
7. Can you walk me through your workflow while creating a web page? What are your first 5 steps when taking on a new project?
8. What technical complications have you faced recently and how did you tackle this challenge?
9. What steps have you taken in your last project in order to support the reusability of your code? Are there any specific programming models that you specifically like to follow? Particularly in terms of functional programming or test-driven improvement?

Examples of Technical Questions

Once you have briefly introduced yourself, there comes a part of technical questions. These questions will mainly relate to frontend development, but might also include questions about backend, potential issues and your problem solving style.

1. What version control systems are there? How can you share code between systems?
2. Name 4 ways to decrease the page load time.
3. What does the abbreviation CORS stand for? What issues CORS is made to solve?
4. Talk about what ARIA and screen readers are. How would you make a site more accessible?
5. What are the characteristics of doctype?
6. What are the main building blocks of HTML5?
7. Talk about the difference between localStorage, cookies, and sessionStorage.
8. What are the data-attributes used for?
9. What should be operated with extra caution – engineering or developing for multilingual sites? How do you manage a page with content in multiple languages?
10. Explain the concept of progressive rendering?
11. Describe how this concept works in JavaScript? How does is impact classes, and how does it go with functions?
12. Define the ascent and interception of events (focus on event bubbling and event capturing).
13. What is the variable hoisting?
14. Set out the difference between:

function Animal() {}

var animal = Animal()

var animal = new Animal()

15. What is the main difference between native and host objects? What is the common use case for anonymous functions?
16. Describe how prototypal inheritance works in JavaScript.
17. What is closure, why and how to use it?
18. Outline the difference between null and undefined?
19. Specify the difference between == and ===?
20. What is Webpack and what problems it solves?
21. Tell me about the last time you used a frontend framework or library? What project was that for?

Summary

On the whole, we believe that these questions can really help you better understand what to expect from a standard JavaScript interview. Make sure you look through this list before you go.