1import React, { useLayoutEffect, useState } from 'react';
2
3function useWindowSize() {
4  const [size, setSize] = useState([0, 0]);
5  useLayoutEffect(() => {
6    function updateSize() {
7      setSize([window.innerWidth, window.innerHeight]);
8    }
9    window.addEventListener('resize', updateSize);
10    updateSize();
11    return () => window.removeEventListener('resize', updateSize);
12  }, []);
13  return size;
14}
15
16function ShowWindowDimensions(props) {
17  const [width, height] = useWindowSize();
18  return <span>Window size: {width} x {height}</span>;
19}
20