# Hello World in React Native

It's a default programming practice to start our journey of learning of new language by printing a "Hello World!".

We will do no exceptions! Let us start our application with a "Hello World!".

The two files we discovered in the previous blog that is super important to start building our application are ***index.js*** and ***App.js.***

Our initial index.js file looks like this

```javascript
import {AppRegistry} from 'react-native';
import App from './App';
import {name as appName} from './app.json';

AppRegistry.registerComponent(appName, () => App);
```

The **AppRegistry** is the JS entry point to running all React Native apps. App root components should register themselves with ***AppRegistry.***

So we mostly need to change the contents inside the **App.js** file**.** Let us inject the below piece of code into our **App.js**

```javascript
/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 *
 * @format
 */

import React from 'react';
import {SafeAreaView, Text, View} from 'react-native';

function App(): JSX.Element {
  return (
    <SafeAreaView>
      <View>
        <Text>Hello reat native!</Text>
      </View>
    </SafeAreaView>
  );
}

export default App;
```

To run our application, we're going to use our Android device. Make sure to turn the developer mode enabled and USB Debugging turned on. Open the integrated vscode terminal and write,

```bash
npm start
```

It will build our application and automatically install the app into our Android device and run it. The result is shown below. The device I'm using is Realme 5 pro.

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1681496588782/0a2de132-f383-418f-b887-ac36b3a4a2c3.jpeg align="center")

So that's a wrap. We saw how to write and run our first react-native application and run directly into our phone.