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In this article, we’ll cover some popular ReactJS interview questions and answers to help you prepare and get ready for your upcoming technical interview.
Here’s what we’ll discuss in this article:
This section will look at some popular ReactJS interview questions, mostly asked at Java developer and SQL developer interviews.
This is a popular ReactJs interview question asked in Java interviews. ReactJs offers a host of advantages to front-end developers. They include:
The Virtual DOM in ReactJs is when a virtual representation of the real DOM is placed inside the memory. The virtual DOM is then synced with the real or actual DOM by the ReactDOM library.
This is yet another frequently asked ReactJS interview question. Lifecycle phases in ReactJS allow developers to alter the phase of a given lifecycle. The different lifecycle phases that components or blocks of code go through include:
The lifecycle methods under the Mounting lifecycle phase are:
The methods under the Updating lifecycle phase are:
There is just one lifecycle method associated with the Unmounting Phase — componentWIllUnmount
The steps involved in creating the React app include:
An event is an action performed by the user or computer. Any action that involves pressing a key, mouse clicks, or typing out sentences, classify as events. React events are in camelCase, unlike lowercase in HTML.
A component in react is a block of code that serves as a building block of the React application. Components are part of the UI and split user interfaces into multiple reusable parts, processing each part individually.
Knowing the answer to this ReactJS interview question is essential. The two types of components in React are - Functional Components and Class Components.
Synthetic events in React are events that combine native events of different browsers into a single API, thereby ensuring consistency.
This is a common ReactJS interview question asked at Java interviews. In React, the traversal of lists can be accomplished through the map() function.
Keys are extremely helpful in identifying lists and changes that have been made to items in lists. They also signify which components in the library need to be re-rendered based on the corresponding updates and prevent other items from unnecessarily being re-rendered.
We’ve compiled a list of the most commonly asked ReactJS interview questions and answers in this article. We hope this helps you prepare for your technical interview.
Q1. What is ReactJs, and what is it used for?
Q2. When can you expect to be asked ReactJS interview questions?
Q3. Do you need to have in-depth knowledge of ReactJS while appearing for Java technical interviews?
Q4. What are some concepts around which React interview questions are asked in technical interviews?
Some common concepts around which you’re asked React interview questions at tech interviews are lifecycle methods, events in React, lists, forms, functions, components, and commands used in React.
Q5. What is the use of the Arrow function in React?
The Arrow function helps to write short-form versions of functions in React, saving time and assisting developers in avoiding errors.
If you’re getting ready for a ReactJS interview or any other upcoming technical interview, register for our free webinar to get insightful guidance from industry experts on nailing technical interviews at top tech companies.
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