Top 30+ React Interview Questions and Answers

React interview questions commonly feature at Java developer interviews, mainly front-end interviews, as the framework helps perform a range of front-end programming tasks. This essentially means that if you’re appearing for a technical or coding interview at a top company, knowing answers to common React interview questions is important if you wish to get ahead of the stiff competition.

While developing applications and software programs, choosing the proper framework is crucial to perform tasks. React is one of the most popular JavaScript frameworks that help developers build software programs and applications using Java.  Several features, such as an extensive library, clean abstraction, and reusable components, have made React the top choice for front-end developers across the globe. So if you’re appearing for an upcoming front-end developer interview, make sure to practice answers to common React interview questions to stand out from the competition.

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In this article, we’ll look at some core features of React through some popular React interview questions and answers.  Read on to learn more.

Here’s what we’ll discuss in this article:

• Popular React Interview Questions and Answers
• Additional Sample React Interview Questions
• FAQs on React Interview Questions

Popular React Interview Questions and Answers

In this section, we’ll look at some common React interview questions along with answers.

Q1. What are some benefits of using React?

This is one of the most common React interview questions asked at developer and software engineering interviews. Some benefits of using the React framework include:

• React adheres to a component-based approach. This makes it easy to use reusable UI elements in applications.
• React can build complex UI, both for mobile and web applications.
• It improves the performance of applications.
• Creating UI test cases is easier with the React framework
• Code created using React is more readable because of JSX
• React can be easily integrated with other popular frameworks such as Angular, Meteor, etc.

Q2. What are some limitations associated with using React?

Some limitations with React are:

• The React library is extensive and takes a reasonable amount of time to learn and understand
• Coding can be a bit complex as React uses JSX and Inline templating
• As React is mostly just a library, it doesn’t have the features of a complete network

Q3. What are some prominent features of React?

This is another popular React interview question asked at software engineer interviews, especially front-end developer interviews. Some common features of the React framework are:

React makes use of Server-side Rendering

Data binding is a prime feature in React, and it follows a unidirectional data flow

React makes of the Virtual DOM instead of a Real DOM

Q4. What can’t JSX be read by browsers?

Browsers are built to read JavaScript objects, but in the case of JSX<, it isn’t a real JavaScript object. The JSX file needs to be converted to a JavaScript object using a transformer like Babel to be read by the browser.

Q5. What are components in React, and what are its two types?

Components are blocks of code and are the basic building blocks of React’s UI. The two types of components in React are - Functional Components and Class Components.

Q6. What is the need for using Routers in React?

Routers essentially specify multiple routes when users enter a URL. If the URL matches any route specified in the Router, users are redirected to that particular URL. Routers are needed to create multiple routes so users can be redirected to appropriate pages.

Q7. What do you understand about Redux?

Redux is an elaborate library used for front-end development. Developers extensively use it to build a range of applications and software. Applications built using Redux can run on multiple environments and are easy to test.

Q8. What are the prime features of Redux?

This is another popular React interview question asked at technical interviews at top companies.

State management: The application state is stored within a state tree or an object in a single store. This makes it extremely easy to track changes made to application code while also assisting seamless debugging.

Redux uses Pure functions: Pure functions are functions whose real value is dependent on the value of their arguments. Pure functions are required to understand how state trees are transformed.

The application state is read-only: Another core feature is that application states can be changed only through a JavaScript object that performs the required action.

Q9. What do you understand about Flux?

Flux is an architectural setup that controls derived data and facilitates communication between different components through a central store. Flux enforces a uni-directional data flow and has complete authority over the central store. If data needs to be updated in multiple places in the application, it has to be done through Flux.

Q10. What are the two main advantages of using Flux?

The two main advantages of using Flux are that it makes the application more stable by effectively performing data updates. By ensuring uniformity, it also prevents runtime errors that may occur due to incorrect code updations.

Q11. What are Pure components in React?

Pure components in React maintain code simplicity and the application’s performance. Pure components in React can replace any component that possesses a render().

Q12. What are Higher-Order Components in React?

Higher-Order Components, commonly referred to as HOCs, are pure components in React that wrap other components within them. They enable component logic to be reused whenever necessary. HOCs are capable of wrapping dynamically provided child components in React.

Q13. What are some functions that can be performed using HOC?

With HOC, you can:

• Manipulate props
• Manipulate and abstract the application State
• Reuse and manipulate code, including bootstrap abstraction
• Reder Hijacking

Q14. What are synthetic events in React?

Synthetic events are objects that behave like cross-browser wrappers. They are used to combine behaviors of multiple browsers into a single API. They ensure that events display and exhibit consistency across different browsers.

Q15. What are References in React?

References in React help to store a particular element or component. The component is then returned using the render() function. References come into use when DOM measurements need to be used or when certain methods need to be added to components.

Take a look at some React Native Interview Questions for tech interview preparation.

Additional Sample React Interview Questions

In this section, we’ll look at some additional React Interview Questions that you can practice for your upcoming technical interview.

1. What is the purpose of render() in React?
2. How is React different from the Angular framework?
3. What are Props in React?
4. What is a State in React?
5. State the differences between States and Props in React
6. How do you update the State of a given component in React?
7. What is an event in React?
8. How would you modularize code in React?
9. State the differences between Controlled and Uncontrolled components in React?
10. What do you understand about the “single source of truth” in React?
11. What do you understand by Prop-drilling in React?
12. What are Error boundaries in the React framework?
13. Explain the differences between Controlled and Uncontrolled Components in React
14. What do you understand about the Strict Mode in React
15. What is the use of Webpack in React?
16. What do you understand about Babel in React?

Here’s a list of top ReactJS Interview Questions and Answers for you to practice.

The React interview questions listed above will help you understand the types of questions you can expect in your upcoming Java interview. Knowing how to use popular tools like React, Spring, and others to design and develop Java programs is critical for standing out in technical interviews.

FAQs on React Interview Questions

Q1. What type of React interview questions can you expect in technical interviews?

React interview questions that you can expect in tech interviews include React components, UI, features of React, events, lifecycle methods, stateful and stateless components, props, JSX, and embedding components, among other concepts.

Q2. Are React interview questions asked in Python interviews?

Since React is a JavaScript library, you won’t be asked React interview questions at Python interviews. Your knowledge of the React framework is only tested in Java developer interviews.

Q3.   What type of Templating does React use?

React employs Inline Templating. This is one of the reasons why it is slightly complex to code within the React framework.

Q4. Are React Interview Questions asked at Design interviews at FAANG companies?

Yes, if you are a Java developer, you can very well be asked React interview questions at design interviews, primarily because React is one of the major frameworks used for front-end development.

Q5. What is the need for using the render() function in React?

The render() function in React is used to return single elements that represent native DOM elements. The render() function returns the same value whenever called.

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