10 JavaScript Tricks Every Developer Should Know in 2026

10 JavaScript Tricks Every Developer Should Know

Short, sharable tricks with copy-paste code. Save this post — share it!

Quick list

• 1. Short-circuit default values
• 2. Destructuring defaults
• 3. Optional chaining & nullish coalescing
• 4. Toggling booleans
• 5. Async IIFE for top-level await
• 6. Grouping logs with console.group
• 7. Debounce helper pattern
• 8. Use Set to dedupe arrays
• 9. Object.fromEntries for transforms
• 10. Short async error handling trick

1) Short-circuit default values

const name = userInput || 'Guest'; 
// but beware: treats '', 0, false as falsy. Prefer nullish if you want only null/undefined:
const name2 = userInput ?? 'Guest';

2) Destructuring defaults

const { a = 1, b = 2 } = options || {};

3) Optional chaining

const phone = user?.contact?.phone ?? 'N/A';

5) Async IIFE for top-level async

(async () => {
  const r = await fetch('/api/data');
  const data = await r.json();
  console.log(data);
})();

7) Debounce helper

function debounce(fn, wait=300){
  let t;
  return (...args) => {
    clearTimeout(t);
    t = setTimeout(()=> fn(...args), wait);
  };
}

9) Object transforms with fromEntries

const entries = Object.entries(obj).map(([k,v]) => [k.toUpperCase(), v]);
const newObj = Object.fromEntries(entries);

10) Short async error handling

const to = (p) => p.then(data => [null, data]).catch(err => [err]);
const [err, data] = await to(fetchData());
if(err) return console.error(err);