ReactJS checked Attribute

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

In this article, we will know how to use checked or defaultChecked attribute in checkbox input in React.js.

The checked attribute can be used with a checkbox or RadioButton element.

Creating React Application And Installing Module:

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 1: 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'; 

// Defining our App Component 
const App = () => { 

  // Returning our JSX code 

  return <> 

    <div> 

      <h1>GeeksforGeeks</h1> 

        Input: <input type='checkbox' checked={true} /> 

    </div> 

  </>; 
} 

// Exporting your Default App Component 

export default App

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:

Example 2: Now write down the following code in the App.js file. Here, App is our default component where we have written our code.

Javascript

import React from 'react'; 

// Defining our App Component 
const App = () => { 

  // Returning our JSX code 

  return <> 

    <div> 

      <h1>GeeksforGeeks</h1> 

        Input: <input type='radio' checked={true} /> 

    </div> 

  </>; 
} 

// Exporting your Default App Component 

export default App