const app = document.getElementById('app');
app.innerHTML = `
<h1>JavaScript DOM</h1>
<ul id="list">
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
</ul>
`;
const listItem = document.querySelector('#list li');
// Any DOM Nodes
console.log(listItem.nextSibling);
console.log(listItem.previousSibling);
// Any Element Nodes
console.log(listItem.nextElementSibling);
console.log(listItem.previousElementSibling);
来源:https://www.cnblogs.com/Answer1215/p/12596292.html