[HTML 5] Inserting DOM element

const app = document.getElementById(app);
app.innerHTML = `
  <h1>JavaScript DOM</h1>
`;

const div = document.createElement(div);
const span = document.createElement(span);
const p = document.createElement(p);
const i = document.createElement(i);
const b = document.createElement(b);

div.append(span);
div.prepend(p);
// p.before(i);
p.after(i);

// Before: old way using insertBefore
// i.parentNode.insertBefore(b, i);

// After: old way using insertBefore + nextSibling
i.parentNode.insertBefore(b, i.nextSibling);

console.log(div);