I'm getting started with reactJS.
import React from 'react';
import ReactDOM from 'react-dom';
var App = ()=>{
return <div> Hello !!</div>
}
ReactDOM.render(<App />, document.getElementById('root'));
In every tutorial or project, everyone is doing import React from 'react';, but nobody is using React in the current file index.js.
...but using nowhere React in current file index.js
If the question is "Why does it has import React from 'react'?", the answer is: That source code isn't using React directly, but the version of it once it's transpiled is, because once the JSX is transpiled, that looks like this (if we just transpile the JSX, not the ES2015 stuff):
import React from 'react';
import ReactDOM from 'react-dom';
var App = () => {
return React.createElement(
'div',
null,
' Hello !!'
);
}
ReactDOM.render(React.createElement(App, null), document.getElementById('root'));
Note the use of React.createElement. The JSX <App /> syntax is just sugar for that.
I think that's probably because when transform jsx syntax, you can actually see for example: <div className="exp"><img /></div>, will transform into:
React.createElement('div', {className: 'exp'}, React.createElement('img'));
So, this will need React object.
