30-seconds-of-code/snippets/useComponentDidMount.md

title, tags, expertise, author, cover, firstSeen, lastUpdated

title	tags	expertise	author	cover	firstSeen	lastUpdated
React useComponentDidMount hook	hooks,effect	beginner	chalarangelo	blog_images/highlands.jpg	2020-01-03T15:56:54+02:00	2021-10-13T19:29:39+02:00

Executes a callback immediately after a component is mounted.

• Use the useEffect() hook with an empty array as the second argument. This will execute the provided callback only once when the component is mounted.
• Behaves like the componentDidMount() lifecycle method of class components.

const useComponentDidMount = onMountHandler => {
  React.useEffect(() => {
    onMountHandler();
  }, []);
};

const Mounter = () => {
  useComponentDidMount(() => console.log('Component did mount'));

  return <div>Check the console!</div>;
};

ReactDOM.render(<Mounter />, document.getElementById('root'));