useEffect example could use something different like scrollY or scrollX.

The useEffect example in the "Synchronizing with Effects" could use a different example, maybe like a window.scrollX or a window.scrollY instead of e.clientX and e.clientY as they don't exist on a scroll event and cause it to show undefined on scroll event.

useEffect(() => { function handleScroll(e) { console.log(e.clientX, e.clientY); } window.addEventListener('scroll', handleScroll); return () => window.removeEventListener('scroll', handleScroll); }, []);

在“Synchronizing with Effects”文档页面中找到 useEffect 示例，并检查其滚动处理程序如何读取事件属性。更新示例以使用 issue 中描述的滚动位置，然后验证渲染后的示例不再为滚动事件记录 undefined 值。