React state hook that returns the previous state as described in the React hooks FAQ.
import {usePrevious} from 'react-use';
const Demo = () => {
const [count, setCount] = React.useState(0);
const prevCount = usePrevious(count);
return (
<p>
Now: {count}, before: {prevCount}
</p>
);
};
const prevState = usePrevious = <T>(state: T): T;