React.js Developer Interview Questions

React.js Developers design and implement user interface components for JavaScript-based web and mobile applications using the React open source library ecosystem. These skilled front-end developers are involved in all stages of interface component design, from conception through to final testing.

Whether you're a job seeker preparing to be interviewed for the role of React.js Developer or an employer preparing to interview candidates for React.js Developer position, these React.js Developer interview questions will help you prepare yourself for the job interview session.

React.js Developer Interview Questions

Below are a list of some skill-based React.js Developer interview questions.

1. What are the benefits of using React.js for user interface design and integration?
2. If you were asked to create a component that displays the current time, what would you name it and what would you include in the component?
3. What would you do if you were working on a React project and you encountered a bug that you couldn’t fix?
4. How well do you understand the concept of props and why they’re important?
5. Do you have experience using inline styling in React?
6. When would you use a conditional in a React component?
7. We want to make sure our React components are as efficient as possible. What is the best practice for removing redundant code?
8. Describe your process for debugging a component that isn’t working.
9. What makes React so popular among developers?
10. Which version of React.js do you prefer and why?
11. How often do you update your knowledge of React.js and other programming languages?
12. There is a new version of React that offers new features. Do you think you would be able to quickly learn how to use it?
13. What is JSX?
14. Can web browsers read JSX directly? 
15. What is the virtual DOM?
16. Why use React instead of other frameworks, like Angular?
17. How do you create a React app?
18. What is an event in React?
19. How do you create an event in React?
20. What techniques should you use to define and develop user-interface components for mobile applications?
21. What application interface components did you design in your previous job?
22. Are you familiar with the Flux architecture?
23. What are the benefits of using React over other JavaScript libraries?
24. How do you determine which components to use for a given project?
25. What is the difference between a state and a property?
26. Provide an example of when you would use a function as a property.
27. What are synthetic events in React?
28. How is React different from React Native?
29. What is the use of render() in React?
30. What is a higher-order component in React?

React.js Developer Interview Questions and Answers

Every interview is different and the questions may vary. However, there are lots of general questions that get asked at every interview.

Below are some common questions you'd expect during React.js Developer interviews. Click on each question to see how to answer them.

1. What is Your Greatest Strength?
2. Are You a Leader or a Follower?
3. What is Your Greatest Weakness?
4. Why Should We Hire You?
5. Why Do You Want To Leave Your Current Job?
6. Why Do You Want This Job?
7. Tell Me About Yourself
8. Do You Have Any Questions for Us?
9. What Is Your Greatest Accomplishment?
10. What is Your Salary Expectation?