componentdidupdate hook equivalent code example
Example 1: componentdidupdate in hooks
const App = props => {
const didMountRef = useRef(false)
useEffect(() => {
if (didMountRef.current) {
doStuff()
} else didMountRef.current = true
}
}
Example 2: component did update hooks
import React, { useState, useEffect } from 'react';
function Example() {
const [count, setCount] = useState(0);
// Similar to componentDidMount and componentDidUpdate:
useEffect(() => {
// Update the document title using the browser API
document.title = `You clicked ${count} times`;
},[count]); // use dependency array to watch for state changes on this part of state
return (
<div>
<p>You clicked {count} times</p>
<button onClick={() => setCount(count + 1)}>
Click me
</button>
</div>
);
}