Running this command:
npx react-native init AwesomeProject
In the App.js file I don't understand 2 lines:
import React from 'react';
import type {Node} from 'react'; // 1
import {
SafeAreaView,
ScrollView,
// ..... Code ....
const App: () => Node = () => { // 2
// ..... Code ....
export default App;
Importing type Node
Following Is there a point to doing 'import type' rather than 'import' with Flow?, I understand that such import is used to import a type of object, for instance:
import type { Array, Object, ... } from 'wherever';
To be honest I am more concerned on the next point (probably If I understand that I would automatically get the this as well).
const App: () => Node = () =>
All that I see is that App is a variable which references a function that returns an Object of type Node which this Object s also a function. Does it wrap the App into a 'React' instance or something?
What does
const App: () => Node = () =>do and why you would want to use it?
If we remove the types, the code is:
const App = () => {
// ... code
}
This is a react functional component.
Then on top of that is added a type: () => Node. This means it's a function that takes no parameters and returns a react Node. Types help with development by letting the computer analyze the code better, and point out bugs sooner (before even running the code)