Modern JavaScript: 10 ES2024+ Features You Should Be Using

JavaScript has changed more in the last five years than in the previous twenty. Here are the modern features that genuinely make your code shorter, safer, and easier to read.

1. Optional chaining — user?.profile?.name
2. Nullish coalescing — value ?? "fallback"
3. Logical assignment — a ??= 10
4. structuredClone() for deep copies
5. Array.prototype.at(-1) — last element
6. Object.groupBy() — group an array by key
7. Top-level await in ES modules
8. Promise.withResolvers()
9. String.prototype.replaceAll()
10. Private class fields with #

Examples

const last = arr.at(-1);
const grouped = Object.groupBy(users, u => u.role);
const copy = structuredClone(obj);