Answers to React Interview Questions

React is a declarative, efficient, and adaptive front-end JavaScript framework that was developed by Facebook in 2011. It makes advantage of the component-based approach to build reusable UI components, especially for single-page apps.

React Is What?

React, a well-liked JavaScript library, debuted in 2011. Front-end development is its primary application, which was created by Facebook developers. The component-based approach used by React ensures that you may create components with a high degree of reusability.

For creating and designing intricate mobile user interfaces and online apps, React is well recognized or you can hire react js developers for this job.

What Are the Benefits of Utilizing React?

  • React renders the view using virtual DOM, which increases performance: Virtual DOM is a virtual replica of the real DOM, as its name indicates. A new virtual DOM is built each time the data in a react app changes. It takes far less time to create a virtual DOM than it does to render the UI in the browser. As a result, the app’s effectiveness is enhanced by the usage of virtual DOM.
  • Comparing React to frameworks like Angular: Its learning curve is more gradual. Using React, anyone with a basic understanding of javascript may begin developing online applications.
  • SEO-friendly: React enables designers to create interactive user interfaces that are simple to utilize in a variety of search engines. Additionally, it enables server-side rendering, which improves an app’s SEO.
  • Reusable components: React develops apps using a component-based design. Components are autonomous, reusable chunks of code. These parts can be used by several apps with related capabilities. The rate of development is accelerated by the reuse of components.
  • Freedom: React gives you the freedom to select the tools, libraries, and architecture for constructing an application in accordance with your requirements from a vast ecosystem of resources.

JSX: What Is It?

The term “JSX” refers to JavaScript XML. It’s a React module that makes it possible to write JavaScript code that looks like HTML. It makes it easier to interpret HTML files. The React application is strengthened and made faster by the JSX file. JSX gives you the ability to write XML-like syntax in the same file where you write JavaScript code. These expressions are then translated into JavaScript code using preprocessors (also known as transpilers like Babel). Like XML/HTML tags, JSX tags also have a tag name, attributes, and children.

What Are “props”?

Properties in React are referred to as props. Since they are read-only, they must be maintained pure, or immutable. Throughout the program, they are continuously transferred from the parent to the child components. A prop can never be returned from a child component to a parent component. This aids in preserving the unidirectional data flow and is frequently used to portray the data that is constantly created:

What Do You Mean When You Say “virtual DOM”?

A virtual DOM is a minimal JavaScript object that serves as an in-memory simulation of the real DOM. It serves as a transitional stage between calling the render function and the screen’s components being shown. The components, their characteristics, and the content are listed as objects with properties, much like a node tree. In response to changes in the data model brought on by different users or system activities, the render function first generates a node tree of the React components and then updates it.

The React useState Updates How Frequently? Why?

Because developers useState to speed up the process by creating queues, React pauses updating changes. Candidates should be aware that useState updates do not instantly implement changes to the state object; instead, they happen asynchronously. In addition as of 2022, Node.js surpassed React.js as the most popular web framework among software engineers globally.

Is There Anything Wrong with Utilizing React?

The following list of restrictions applies while using React:

  • It is difficult to write the code since JSX and inline template formatting are utilized.
  • Its syntaxes and techniques could be difficult for beginners to comprehend.
  • The library has a potentially obscene quantity of knowledge.
  • Due to the fact that React is only a basic library and not a complete framework, dependencies are necessary.


Hiring top talent will be a stress-free task with the help of this set of challenging React.js interview questions. To assess your applicants, create your own list of questions based on the ones you need to be answered.

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