ReactJS unmountComponentAtNode() Method

React.js library is all about splitting the app into several components. Each Component has its own lifecycle. React provides us with some in-built methods that we can override at particular stages in the life-cycle of the component.

In class-based components, the unmountComponentAtNode() method Remove a mounted React component from the DOM.

Creating React Application:

• Step 1: Create a React application using the following command.

  npx create-react-app foldername
  
  

• Step 2: After creating your project folder i.e. foldername, move to it using the following command.

  cd foldername
  
  

Project Structure: It will look like the following.

Example: Now write down the following code in the App.js file. Here, App is our default component where we have written our code.

App.js

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

// Exporting your App Component
export default function App() {

  // Function to unmount root component
  function unm() {
    ReactDOM.unmountComponentAtNode(document.getElementById("root"));
  }

  return (
    <div>
      <h1>GeeksforGeeks</h1>
      <div>Hi Geek, this is the rendered content</div>
      <button onClick={unm}>Unmount</button>
    </div>
  );
}

Step to Run Application: Run the application using the following command from the root directory of the project:

npm start

Output: Now open your browser and go to http://localhost:3000/, you will see the following output:

Reference: https://react.dev/reference/react-dom/unmountComponentAtNode