React js interview questions and Answers
ReactJS is a JavaScript library for building reusable User interface components. It is a template-based language combined with different functions that support the HTML. Our recently updated React Interview Questions can help you crack your next interview. This means the result of any React's operation is an HTML code. You can use ReactJS to build all kinds of single-page applications.
| Short Questions About React | |
|---|---|
| What is the latest version of React? | 18.0, released on March 29, 2022. |
| When was React first released? | 29th May 2013 |
| React JS is Created By | Jordan Walke |
| License of ReactJS | MIT License |
React Developer Interview Questions
Flux is an illustration that helps to maintain a unidirectional data stream. It also controls construed data unique fragments and makes them interface without creating issues. The configuration of Flux is insipid and is not specific to applications.
The server needs to be regularly monitored for updates. The aim is to check for the presence of new comments. This process is considered as pooling. It checks for the updates almost every 5 seconds. Pooling helps keep an eye on the users and ensure there is no negative information on servers.
If your component has a state or lifecycle method, use Class component. Else, a Functional component.
Enclosing the multi-line JSX expression is the best option. Sometimes it becomes necessary to avoid multi-lines in order to perform the task reliably and for getting the expected results.
No. This is because the word Class is an occupied word in JavaScript. If you use the word Class JSX will get translated to JavaScript.
Note: Before getting confused with the plethora of react coding interview questions, you need to ensure the basics. This question will help you to understand the core basics of react and make you even more confident enough to jump onto the advanced questions.
Yes. This is a complex process, and the best way to do it is by using a spread operator.
React is a JavaScript Library which is used to show content to user and handle user interaction.
Component is a building block of any React app which is made by either JavaScript Function of Class. Ex. Header Component, Footer Component etc.
There are two types of Components.
- Function Based Component
- Class Based Component
Class Based Component is the JavaScript Class. In these Components we extends the JavaScript predefined class into our component.
Import React,{Component} from ‘react’;
class ABC extends Component {
render(){
return(
<div>
<h1>Hello World</h1>
</div>
);
}}
export default ABC;
A higher-order component or HOC in React is basically an advanced technique used for reusing component logic. HOCs are not a part of the React API. They are a pattern emerging from the React's compositional nature.
Top 20 React.js Interview Questions
Here you will find the list of Top React interview questions, which were written under the supervision of industry experts. These are the most common questions and usually asked in every interview for the role of the React Developers.
- What is HOC?
- What are the difference between Rest and Spread Operator?
- What are the key benefits of using Arrow functions?
- What is Pure Component?
- What are Controlled and Uncontrolled components with example?
- What is Refs?
- What is the difference between class based component & function based components?
- How to work React?
- Why virtual Dom is faster than real dom?
- How does virtual Dom work in react?
- What are the difference between null & undefined?
Conclusion
Now that you have read all the react questions, it is time for you to go towards the next level. Applying for a developer position would require you to actually code and not just give answers to theoretical questions.
That’s why you should enhance your skills by complementing the above react developer interview questions with a practical mindset. Start coding small stuff, get your concepts crystal clear. It’s all about how you can apply your knowledge in different projects. Code and code, that’s the secret to winning the dream job!