Top 20 Common React Interview Questions & Answers for 2024

When appearing for any interview, the preparatory phase plays an essential role in helping you secure a job. The same is the case with React development jobs, where you need to have advanced knowledge of this framework and library to reach your dream position. To assist you in this regard, we will give answers to some of the most commonly asked React developer interview questions to improve your preparation.

React Interview Questions For Freshers

If you’re gearing up for your first React interview question and answer session, familiarize yourself with some general concepts. Here, we will discuss some questions that typically cover fundamental concepts and practical scenarios essential for developers starting out in React. So, review these questions to feel confident and prepared for your interview, ensuring you’re ready to seize the opportunity.

Question 1. What do you know about React.js and its popularity among developers?

To start the interview, hiring managers may want to judge your basic knowledge about this platform with this easy React interview question. So, you can display your wisdom by explaining that React.js is a popular JavaScript library developed by Facebook for building user interfaces.

While talking about its popularity among developers, mention that it has component-based architecture for easier maintenance. Other than that, its flexibility allows integration with other frameworks and libraries to make it a preferred choice for all applications.

Question 2. Can you describe the significant benefits of React.js?

While answering this basic interview question on React.js, you need to list down the following benefits to impress the interviewer:

Component-Based Architecture: With this type of architecture, React allows reusable components for more maintainable and scalable codebases.
Virtual DOM: React’s virtual DOM efficiently updates and renders components to deliver faster performance by minimizing direct manipulation.
Strong Community and Ecosystem: Through an active community, developers can benefit from abundant resources, libraries, and tools.
State Management: Using tools like Redux or Context API, React facilitates efficient state management to handle complex application states.

Question 3. List down some of the significant features of the React.js programming library

The purpose of this React developer interview question is to assess your knowledge of various React.js features. Rather than detailing any specific feature, you should list multiple names to create a positive impression.

JSX
Virtual DOM
One-Way Data Binding
Lifecycle Methods
Context API
React Router
Redux Integration

Question 4. As a fresh developer, what kind of limitations can you face while using React.js?

Here, you need to explain all the limitations a new developer might face while utilizing React for programming. While answering this React coding interview question, we recommend you talk about all these drawbacks.

Steep Learning Curve: Beginners may find its concepts and ecosystem complex to learn and master.
Poor Documentation: While doing rapid updates and frequent changes, you can experience outdated documentation.
JSX Barrier: JSX syntax can be off-putting to developers who are not familiar with this XML.
Boilerplate Code: Setting up a React project often requires a significant amount of initial configuration and boilerplate code.
Dependency on Third-Party Libraries: React often relies heavily on third-party libraries, which can introduce compatibility and maintenance issues.

Question 5. How can you elaborate on the concept of React hooks?

For a fresher candidate, this React interview question may sound a bit tricky. However, you don’t have to worry because we will familiarize you with this concept so that you can answer this question during the interview.
Generally speaking, these hooks let you use state and other React features without writing a class. In addition, they enable functional components to manage local states, perform side effects, and tap into React’s lifecycle.

Question 6. Elaborate the concept of JSX in the context of React

You can answer this React.js interview question. You should explain that JSX represents a syntax extension for JavaScript, which is used in React to describe the UI structure. Other than that, it allows developers to write HTML-like code within JavaScript to visualize the component structure.

After creating React elements, you can easily update the interface by reconciling the differences between virtual and actual DOM for optimal rendering performance.

Question 7. Can you explain the main distinguishing points between React.js and React Native?

Start answering this React developer interview question by mentioning that both these frameworks are developed by Facebook but serve different purposes. On the one hand, React.js helps you build web applications with HTML elements like “div” and “span.” React Native, on the other hand, assists in building mobile applications for iOS and Android by rendering them to native mobile components instead of web elements.

While React.js uses CSS for styling, React Native uses a style system similar to CSS but optimized for mobile. Despite these differences, both frameworks share a similar syntax and use components and props to manage UIs.

Question 8. Describe the two different kinds of React components

During a React interview question and answer session, the interviewer will ask this question to test your basic knowledge. Therefore, you need to explain the two types of components associated with the React library and framework.

Functional Components: These are JavaScript functions that accept props as arguments and return React elements to describe the interface.
Class Components: With these ES6 classes, developers can carry out state management and lifecycle methods in addition to rendering interfaces based on props and state.

React Intermediate Interview Questions

Intermediate-level React developers aiming to secure a new role should prepare some technical interview questions tailored for them. These React interview questions typically cover slightly advanced concepts and scenarios relevant to web development using React. So, we recommend you go through these solutions to be confident during your interview.

Question 1. Can you explain the central role of Fragments in the React.js framework?

When applying for a better position, you will be asked tough interview questions on React.js to test your knowledge. To display your development acumen, explain that Fragments allows you to group multiple children elements without adding extra nodes to the DOM. Apart from that, they serve the role of improving the structure of your component’s render method by enabling you to return multiple elements in a single render output.

In addition, they are instrumental when you need to render a list of elements without a wrapper. These Fragments also assist in maintaining clean JSX syntax while avoiding unnecessary elements in the DOM tree for improved performance.

Question 2. Explain the process through which browsers read JSX files

As an experienced developer, you need to know the answer to this technical React interview question. Interviewers will expect you to know browsers do not directly read JSX files. Instead, JSX is transpiled into regular JavaScript using tools like Babel before it is executed in the browser. This allows developers to write code using JSX syntax while still ensuring compatibility with all browsers.

Question 3. Clarify the major differences between the terms createElement and cloneElement

The interview will ask about the differences between two technical terms to test your knowledge related to them. Answering this React coding interview question, you need to mention that both methods work with elements in React, but they serve different purposes. “createElement” helps you create a new React element from scratch by taking children as arguments and returning a new element.

“cloneElement,” on the other hand, does its job by cloning an existing React element. It allows you to modify the props and children of the cloned element to apply minor changes to an existing element without recreating it from scratch.

Question 4. How can you explain the various stages of a React component’s lifecycle?

A senior developer will be able to divide the lifecycle of a React component into three main phases. Therefore, you need to detail the following phases while answering this React developer interview question:

Initial Rendering Phase: Through this phase, you can begin the creation of a component’s life within the DOM.
Updating Phase: After you mount components into the DOM, the updating phase is entered. During this phase, the component can re-render in response to changes in its props or state.
Unmounting Phase: In the final phase, the component is removed from the DOM and destroyed.

Question 5. Describe ways through which you can share data between components in React

Through this technical interview question on React.js, interviewers will try to judge your problem-solving capability. As a senior developer, you should know that data sharing between components can be achieved by passing data from parent to nested child components via props.

Alternatively, for more complex applications, React Context API provides a centralized way to share state across components without manually passing props. Other than that, Context allows data to be accessed by any nested component that subscribes to it, simplifying data management and reducing prop drilling in large applications.

Question 6. Will you be able to name a few animation packages in React?

If the interviewer only asks you about the names of the packages, make sure to never act over efficiently by starting to explain the terms. Here, all you have to do is name some animation packages that developers can utilize while responding to this React interview question:

React Spring
Framer Motion
React Transition Group
React Motion
Lottie React Native
React Anime

React Interview Questions For Advanced

As an experienced React developer aiming to advance in your career, you should grasp advanced concepts and methodologies relevant to the platform. Senior-level React coding interview questions often dive into intricate details and practical scenarios to assess a candidate’s suitability for the role. Therefore, you need to familiarize yourself with the questions below to demonstrate your expertise and readiness for the position confidently.

Question 1. Clearly state the methods for React app performance optimization

When answering this advanced interview question on React.js, you need to demonstrate your expertise by explaining the following methods.

Use Functional Components with Hooks: As a senior developer, you should know that functional components are generally lighter and easier to optimize than class components. So, make use of hooks like useMemo to manage state and side effects.
Code Splitting: You can also divide your application into smaller chunks to load only the necessary code initially. As a result, this will reduce the initial bundle size and speeds up load times.
Optimize Images and Assets: Developers should also take some steps to compress images and assets to reduce file sizes. To do so, use lazy loading to defer loading non-essential assets.
Optimize Network Requests: To impress the interviewer, you can also recommend minimizing network requests by batching API calls and using GraphQL or REST optimizations.

Question 2. What are the reasons for using keys in Lists while working on React?

During the React interview question and answer session for the advanced developers, you will be judged by the technicality and accuracy of the response. So, we recommend you mention the following reasons if you want to impress the interviewer:

Optimization: Identify which items have been changed or removed to efficiently update the UI without re-rendering all list items.
Stable Identity: Provide a stable identity for each element in the list, helping React distinguish between elements and maintain the component state.
Avoiding State Loss: Prevent the loss of component state or UI state during re-renders by ensuring that React can correctly update.

Question 3. As a senior developer, how can you explain the significant issues with the MVC framework?

To demonstrate your knowledge, start by mentioning that the MVC framework has widespread use cases and benefits, but it presents some significant issues. Afterward, you can proceed to answer this React developer interview question by explaining the limitations developers can face.

Complexity in Large Applications: As applications grow, the separation of concerns in MVC can become blurred.
Testing Challenges: The interconnectedness of models, views, and controllers can make unit testing more difficult.
Scalability Issues: MVC may not scale well for certain types of applications, particularly those with high levels of user interaction and dynamic content.
Performance Overheads: In addition, the abstraction layers in MVC can introduce performance overheads, especially if not optimized properly.

Question 4. How will you describe the behavior of uncaught errors in React 16?

As a senior developer, you should know that error boundaries capture the uncaught errors in components in React 16 to prevent them from crashing the entire application. While answering this React interview question, you can further mention if no error boundary is defined, the errors will cause the whole React component tree to unmount.

Question 5. Describe the method to build a simple counter with the help of React

Interviewers will judge your experience by the quality of the answer you provide for this React coding interview question. So, explain the details of this complex process as described below:

Start by initializing a React state to hold the count value.
Moving forward, you can define JavaScript functions to adjust the count value with the help of setState().
Finally, you can insert HTML buttons into your JSX code and attach “onClick” handlers to trigger these functions.

Question 6. Can you explain the steps needed to display a list using React?

Begin answering this React developer interview question by explaining that first, you need to create a list of items using a JavaScript array. Afterward, developers can use the “Array.map()” method to iterate over each item in the array. Finally, within the map function, return JSX code to render each item to display a dynamic list in your React application.

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Conclusion

In this article, we’ve provided ideal answers to common React developer interview questions to help you secure the job you want. Whether you’re a beginner or a seasoned app developer, the questions covered here will give you an edge in your interview preparation. Additionally, you can enhance your React app and web development skills by utilizing the SDKs provided by ZEGOCLOUD.