react/hook-from-function-fail.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<script src="https://unpkg.com/react@17/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/@babel/standalone@7.14.7/babel.min.js"></script>
</head>
<body>
<p><a href="https://cirosantilli.com/react">https://cirosantilli.com/react</a></p>
<div id="root"></div>
<script type="text/babel">
function helper() {
return React.useState(0)
}
function Main(props) {
console.log('Main');
const [n, setN] = helper()
function handleClick() {
console.log('handleClick');
setN(n + 1)
}
return (
<div>
<div onClick={handleClick}>Click me</div>
<div>{n}</div>
<div>{Math.floor(n / 2)}</div>
</div>
)
}
ReactDOM.render(
<Main />,
document.getElementById('root')
);
</script>
</body>
</html>