Top ReactJS Interview Q/A You Should Definitely Prepare For

Top ReactJS Interview Q/A You Should Definitely Prepare For

From Muhammad Aamir

React is an effective, adaptable, and freely available JavaScript framework library for building quick, lightweight, and scalable online apps. The Facebook software engineer Jordan Walke is responsible for developing Rea

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React is an effective, adaptable, and freely available JavaScript framework library for building quick, lightweight, and scalable online apps. The Facebook software engineer Jordan Walke is responsible for developing React. Hire ReactJS Developers to experience the umpteenth amount of advantages React tags along with it. 

Numerous well-known businesses around the globe offer numerous job openings. Research indicates that React JS currently holds a 7.3% portion of the market.

Facebook's news feed and Instagram's photo-sharing app were the first places it was used in 2011. Web application development is simplified using React for developers having a Javascript background. 

Use the state and other React capabilities without having to write a class by taking advantage of React Hooks.

To put it another way, React Hooks are the functions that will establish a connection between React state and the lifecycle aspects of the function components. Updates to React Hooks are one of the new features included in version 16.8.

ReactJS Interview Questions with Answers

To help you land your dream job, we've compiled a list of some of the most often-asked interview questions and answers related to ReactJS.

  • What is ReactJS? 

Facebook's React was released in 2011 and is a JavaScript library for use in front ends. 

It is component-based, therefore it's easier to create modular UI elements. 

It's put to use in the creation of sophisticated and responsive user interfaces for the web and mobile devices. 

It has one of the largest communities behind it despite being open-sourced very recently (2015).

  • What are some of the benefits of utilizing ReactJS? 

This is a common ReactJS interview question in Java. There are many benefits that ReactJS provides for front-end developers. Those items are: 

  • React makes it possible to reuse previously developed components. Components are merely reusable pieces of code, and React makes it easy for developers to recycle and adapt existing pieces of code as needed.

  • When compared to other frameworks, React's learning curve is much lower. To begin creating applications, you need only a basic understanding of JavaScript and ReactJS. 

  • It's easy for front-end developers to optimise the application or web page's performance with the help of the ReactJS framework, which is very search engine optimization (SEO) friendly. 

As a result of its component-based architecture paradigm, 

  • When using ReactJS, what are the various stages that can occur?

This is another standard inquiry about your experience using ReactJS. The phases of a lifecycle in ReactJS can be changed by the developer. There are several stages in a piece of code or a component's lifecycle, including: 

  • Mounting

  • Updating

  • Unmounting 

  • Can you walk me through the process of making a React app? 

The process of developing a React app consists of the following stages: 

  • The React library can't be installed without the NodeJS file, so make sure you have it on your PC. The React JavaScript library is just one of many that may be found in the node package manager (Npm). 

  • Install the create-react-app package and run it.

  • Getting started is as simple as installing a text editor.

  • To what end does ReactJS render() function serve? 

Render() is required for all React components. An individual React element, standing in for the original DOM node, is returned. 

Multiple HTML elements can be rendered at once if they are contained within a single wrapping tag, like a form>, group>, div>, etc. 

This function must be kept pure, which means it must always produce the same output.

  • Can you explain what we mean by "Virtual DOM"? 

A virtual Document Object Model (DOM) is a straightforward JavaScript object that functions identically to its real-world counterpart. 

Element, attribute, and property information can be shown as nodes in a tree structure. 

It does this by rendering a tree of nodes in React and then updating that tree whenever the underlying data model is modified. Users or the system's behaviours typically set off these shifts.

  • Does using React have any drawbacks? 

The following are certain restrictions that should be kept in mind when working with React: 

  • It's difficult to write code because of JSX and inline template formatting. 

  • Its syntaxes and approaches may be difficult to understand for newcomers. 

  • As impressive as the library's collection of books and other resources is, it may also be intimidating. 

  • Where did the term "Redux" come from, and what does it mean? 

Redux is used to maintain the application's state in a centralised location. 

Typically, this is a JavaScript object that serves this purpose. To make changes to states, it is necessary to push out actions from the application and to create objects that correspond to those actions.

For example:

{first_name: ‘Jaspreet’,

last_name : ‘Kaur’,

age: 23}

Redux saves all information (also called a store).

  • What are the kinds of React component side effects; please elaborate.

The React component can have one of two kinds of unintended consequences. This list includes: 

This effect will be utilized ineffect, which will not prevent the browser's screen from refreshing. Additionally, it makes an app more responsive. Network requests, logging, manual DOM changes, etc., are all examples of such operations. 

Effects that Require Cleanup: After DOM is updated, several Hook effects must be cleaned up. If you want to subscribe to an external data source, for instance, you'll need to clear some memory beforehand. 

Unmounting components is when React is known to perform memory cleanup. However, the effects will be applied to every render() call and not just one in particular. 

That's why it's accurate to claim that the React will clear out the effects from the previous render before executing them the next time around.

Step- up your ReactJS Game With BootesNull 

As a leading ReactJS training provider in Chandigarh and Mohali, BootesNull is here to help you get where you want to go. 

BootesNull is a world-famous IT firm based in Mohali, India that offers mobile app development services to clients all over the world. But we are firm believers in passing on what we've learned to other ambitious software developers. Consequently, we provide ReactJS training in Chandigarh, Mohali vicinity. 

Our training program is open to high school, college, and university students, as well as recent graduates, established professionals, and independent contractors. Our in-depth training program is designed to help each candidate launch a successful and fulfilling career.

We adhere firmly to a world-class training environment that encourages enthusiasm and determination to provide our candidates with the best possible instruction.

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