React Js Interview Questions And Answers for Freshers? Section - 1

React Js Interview Questions And Answers for Freshers? Section - 1

Oct 27, 2022·

2 min read

React Js is the most trending word in the tech industry. React is the most popular front-end technology top Multinational companies are using it in their projects, React is used to build single-page web applications, The main reason why people switch to react is that it is fast, scalable, flexible and modular and if you are preparing for a job interview then this blog is for you. In this article, we have listed out commonReact Js Interview Questions And Answers for Freshers

What is REACT?

React Js is an open-source front-end JavaScript library which is used to build interfaces and handle view layers for web and mobile applications. React follows a component-based approach.

Features of React?

  • React Js uses Virtual DOM instead of Real DOM.

  • Routing allows users to navigate through multiple pages quickly.

  • JSX is used with React to describe what the user interface should look like, It makes writing markup much simpler.

  • Supports server-side rendering.

  • Follows Unidirectional data flow.

  • Uses a composable UI component to develop the view.

What is the difference between states and Props?

The main difference between states and props is subtle. A state is something that you change frequently, whereas props are things that don’t change often.

What will happen if you use setState() in the constructor?

When you use Setstate (); then apart from assigning to the object state React also re-renders the component and its children. It shows errors like: Can only update a mounted or mounting component, That's The reason why this.state to initialize variables inside the constructor.

What are the lifecycle methods that have been deprecated in React v16?

Some of the lifecycle methods are going to be unsafe coding practices and it creates problems with asynchronous rendering.

  • componentWillMount()

  • componentWillReceiveProps()

  • componentWillUpdate()

Why do we need to be careful when spreading props on DOM elements?

While spreading props we run into the risk of adding unknown HTML attributes which is a bad practice. Instead, you can use prop destruct with … rest operator so it will add only the required props.

What are the advantages of React over Vue.js?

React Js has a few advantages over Vue.js:, Gives flexibility in large application development, Testing becomes easy, Suitable for mobile application creation.


The above is the commonly asked React Js Interview Questions and Answers for Freshers. In the Upcoming days, we will also add more Interview Questions and Answers from beginners, and advanced levels to this blog that is prevalent in the Industry.

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