Top 5 Questions You Need to Know For React JS in 2024 | react top 5 most asked interview questions

Preparing for a React interview and aiming to tackle any question with confidence? Great! In this video, we've got you covered with the top 5 React interview questions you must know to ace your next interview. Whether it's grasping React fundamentals or showcasing your problem-solving prowess, these questions are your ticket to standing out and landing that dream web development job. Don't skip out on this crucial info - dive in now and gear up for success!

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Welcome, everyone, to the top 5 most frequently asked interview questions that you should prepare for before tackling any React interview.

Question 1: What is React and how does it work ?

So, React is a JavaScript library. It is a client-side library. It uses the concept of virtual DOM. So whenever a change needs to be made to the real DOM, in that case, the changes are first made to the virtual DOM, and then they are compared with the real DOM. Only those nodes needing changes are updated, hence increasing the overall performance of the operation.

Question 2: What is the difference between a class component and a functional component ?

Class components are normal classes in React which return or render some HTML. Class components have their own states and lifecycle methods whereas functional components are normal React functions which return HTML. They do not have their own state but they can use hooks for state management as well as achieving lifecycle methods. Class components have been deprecated whereas functional components are most widely used in React.

Question 3: What is JSX ?

In React, JSX stands for JavaScript and XML. It enables a user to write XML or HTML inside JavaScript. For example, a Component is a basic example of JSX.

Question 4: What is the virtual DOM in reality ?

So, the virtual DOM is a carbon copy of the real DOM. It is stored in memory and is never rendered. So, it is very easy and fast to make changes to the virtual DOM. Whenever we need to make any changes to the real DOM, we first make the changes to the virtual DOM as it is quick and fast, and then the virtual DOM is compared with the real DOM. This process is done to identify which nodes have been changed, and now only the changed nodes need to be updated in the real DOM, hence increasing the overall performance of the application.

Question 5: What is the difference between state and props ?

So, states can be understood as an internal storage of a component whereas props are there to pass data from the parent component to the child component. States can have a setter as well as a getter, so using those, we can manipulate a state. So, states are mutable whereas props are immutable. They are generally used to pass data from the parent to the child. States are there to store data persistently. During the render, the data stored inside a state never gets lost, but props are there to pass the data and the data never gets changed.

So, these were the differences, and these are the top 5 most asked interview questions that you should prepare for. If you found this video helpful, do like and subscribe. See you in the next video.