JavaScript Environment Requirements

React Backward Javascript Compatibility

It is a Javascript open-source library used for building user interfaces. Single-page websites are based on and react 16 depending on collections like maps and set.

And if you are using old devices with old browsers which do not provide natively(internet explore <11 or internet explorer 11), including a global polyfill in bundled applications such as core-js.

To support earlier browsers, a polyfilled environment for React 16 using core-js may look like this:

import 'core-js/es/map';
import 'core-js/es/set';


import React from 'react';
import ReactDOM from 'react-dom';


ReactDOM.render(
  <h1>Hello, world!</h1>,
  document.getElementById('root')
);

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raf package is used to shim requestAnimationFrame on which react depends:

import 'raf/polyfill';

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You can compile with the help of Online Javascript Compiler for better understanding.

Frequently Asked Questions

Q1) What is react-dom?

The react-dom package used at the top level of your app contains DOM-specific functions and an escape hatch if you need to leave the React model. not every component can use this module.

Q2) What is ReactTestUtils?

ReactTestUtils makes it simple in your preferred testing framework for testing React components.

Q3) What is ReactDOMServer?

This object allows you to render components to static markup and is used on the node server.

// ES modules
import ReactDOMServer from 'react-dom/server';
// CommonJS
var ReactDOMServer = require('react-dom/server');

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Q4) What do you mean by components of react?

React has small components with a reusable code that returns to the page the react element to be rendered.

function Welcome(props) {
  return <h1>Hello, {props.name}</h1>;
}

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Key Takeaways

Don't come to a halt here. Check out our 15 Most Frequently Asked React JS Interview Questions | Coding Ninjas Blog. You can also check out the blog on the Angular vs React: Which One to Better for Your App | Coding Ninjas Blog. Check out some books for react.js Top 10 React.Js books to enhance your web development skills | Coding Ninjas Blog.