React Native start of the project

Execution react-native run-ios command

Will open a local service, load jsbundle file, then go index.js file

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

AppRegistry.registerComponent(appName, () => App); //展示App 组件

Importing is so, then how is it export?

 

Is then registered into the assembly, any component must have a render () method, which returns into view on the main screen