how hook updated the component 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: document.title you clicked count times
import React, { useState, useEffect } from 'react';
function Example() {
const [count, setCount] = useState(0);
useEffect(() => { document.title = `You clicked ${count} times`; });
return (
You clicked {count} times
);
}