where is instance of class created

Question

We are shown the following code:

class HelloComponent extends React.Component{
   render() {
     return(
            <h1>Hello</h1>
     );
   }
}

ReactDom.render(
    <HelloComponent />, document.getElementById('container)
);

Since HelloComponent is a class does ReactDOM.render create an instance?

Answer 1

The ReactDOM.render() method returns a reference to the component.

This mean you can do something like:

const helloComponent = ReactDom.render(
    <HelloComponent />, document.getElementById('container)
);

And have a reference to the component you can use for other purposes if you want.

NOTE: This does not work for stateless/functional components.