33 lines
845 B
Markdown
33 lines
845 B
Markdown
---
|
|
title: React useComponentDidMount hook
|
|
tags: hooks,effect
|
|
expertise: beginner
|
|
author: chalarangelo
|
|
cover: blog_images/highlands.jpg
|
|
firstSeen: 2020-01-03T15:56:54+02:00
|
|
lastUpdated: 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.
|
|
|
|
```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'));
|
|
```
|