[Javascript] Finding Sibling Elements

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);