I'm learning React from a "First Principles" approach. I am concerned that a undefined variable can be rendered in root.render; error prone. Would anyone know why is this allowed? root.render().

Comments

[Oscar]

root.render() should render the base of your application. The base component that gets rendered (usually App.jsx) should never be null. And if you're getting your root like this (or a similar way -- there are probably different ways to go about this):

ReactDOM.createRoot(document.getElementById("root"))

Then as long as your index.html has a <div id="root"></div> in it, document.getElementById("root") won't ever be null either.