App

If you open the default app you can observe that the app.js file looks like

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

export default class App extends React.Component {
   render() {
  return (
     <View style = {styles.container}>
        <Text>Open up App.js to start working on your app!</Text>
        <Text>Changes you make will automatically reload.</Text>
        <Text>Shake your phone to open the developer menu.</Text>
     </View>
  );
   }
}

const styles = StyleSheet.create({
   container: {
  flex: 1,
  backgroundColor: '#fff',
  alignItems: 'center',
  justifyContent: 'center',
   },
});

Output

Hello world

To display a simple message saying “Welcome to Tutorialspoint” remove the CSS part and insert the message to be printed wrapped by the <text></text> tags inside <view></view> as shown below.

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

export default class App extends React.Component {
   render() {
  return (
     <View>
        <Text>Welcome to Tutorialspoint</Text>
     </View>
  );
   }
}