Files
30-seconds-of-code/snippets/useComponentDidMount.md
Isabelle Viktoria Maciohsek eeccde742b Update hook descriptions
2020-11-16 14:17:53 +02:00

28 lines
676 B
Markdown

---
title: useComponentDidMount
tags: hooks,effect,beginner
---
Executes a callback immediately after a component is mounted.
- Use `useEffect()` with an empty array as the second argument to execute the provided callback only once when the component is mounted.
- Behaves like the `componentDidMount()` lifecycle method of class components.
```jsx
const useComponentDidMount = onMountHandler => {
React.useEffect(() => {
onMountHandler();
}, []);
};
```
```jsx
const Mounter = () => {
useComponentDidMount(() => console.log('Component did mount'));
return <div>Check the console!</div>;
};
ReactDOM.render(<Mounter />, document.getElementById('root'));
```