DEV Community

7 New JavaScript Features (And 2 I'm Still Waiting For)

Sylwia Laskowska on June 24, 2026

Remember how I promised you (or rather myself) two weeks ago that from now on I'd only write light, easy posts? Well… I broke that promise 😅 Last w...

Read full post

Pascal CESCATO • Jun 24

But today is finally the day for something a bit lighter.

Lighter?🤔
Hmm… interesting, for sure. Lighter? Depends on your own javascript skills.

And about inclusion in the Top 7 Posts of the Week: the post deserves it, you deserve it. It was really interesting.

Sylwia Laskowska • Jun 24

Thanks, Pascal! Yeah... I think something went slightly wrong with the "lighter" part of this post. Maybe next week I'll finally manage to write something truly lightweight. 😅

And you're right about the migration post. Writing the article itself took quite a while, but compared to preparing the conference talk, that was the easy part! There was a lot of research, testing, refining examples, and trying to distill years of migration lessons into something useful and practical.

So I'm especially happy to see that people found it valuable. 😊

Pascal CESCATO • Jun 24

What you are seeing—and what I see too—is that hard work still pays off: gathering sources, doing your research, incorporating your own knowledge, and pulling it all together—all of this contributes to the richness of an in-depth article and to the recognition of your work, whether through the comments you receive, inclusion in the "Top 7 of the Week," or in many other ways.

Sylwia Laskowska • Jun 24

Exactly! 😄 Maybe it doesn't make us any richer, but at least we get to have great conversations with interesting people in the comments. And that's one of the best parts of writing. 😊

Hemapriya Kanagala • Jun 24

Sylwia, I can tell a lot of work went into this one 😄

I'm not that deep into JavaScript myself, but I still learned a few things from this. It's easy to forget that the language keeps evolving while everyone is busy talking about AI these days.

Thanks for sharing this.

Sylwia Laskowska • Jun 24

Thank you so much! 😊

That's always my goal: to make technical topics approachable and easy to digest, even for people who don't work with JavaScript every day. I'm really glad you found something useful in it!

Daniel Balcarek • Jun 24

Nice, it looks like JS is slowly catching up with “real” languages like C#. 😄🤪 Just joking, of course. 😄

But honestly, Temporal.Now.instant() and using features look amazing. Having them in JS would be great. I hope we get them next year.

Sylwia Laskowska • Jun 24

Haha, exactly! 😄 We're getting closer to the "real languages" every year.

Though honestly, JavaScript will never fully get there, because we'd have to break half the web to do it. 😂

Temporal should make it into ES2027 without much drama, but using is still only at Stage 3, so we'll see. I'm keeping my fingers crossed though!

Daniel Nwaneri • Jun 24

The getOrInsert addition is the one I've been waiting for . That pattern of checking has() then set() then get() shows up everywhere in agent memory implementations and it's always felt like boilerplate that shouldn't exist. Math.sumPrecise() is the other one worth flagging for anyone doing token budget calculations where floating point drift compounds across requests. Good breakdown — the TC39 repository dig on Temporal was worth it.

Sylwia Laskowska • Jun 24

Thanks, Daniel! 😊 That's a great example.

To me, it really shows how these features are catching up with the reality of modern development and helping us write code that's a better fit for today's AI- and agent-driven applications, instead of relying on the same old boilerplate patterns.

Adam - The Developer • Jun 24 • Edited

awesomeeeeee!! this is my favorite now btw:

const meeting =
  Temporal.ZonedDateTime.from(
    "2026-11-03T10:00:00[Europe/Warsaw]"
  );

Sylwia Laskowska • Jun 24

Exactly! 😄 A brave new world where dates actually make sense. 😂

Jack Lee • Jun 24

JavaScript has always felt like a premature baby.
Back in the early days, every project was a collection of hacks, browser quirks, polyfills, and "don't touch this code" comments. Many of today's features aren't innovations so much as missing pieces that should have existed from the beginning.
The surprising thing is not how much JavaScript has changed, but how long it took to grow up.

Sylwia Laskowska • Jun 24

Exactly! 😄 That's actually one of the reasons I've been on a bit of a crusade in my articles lately: making people aware that many of the hacks and workarounds we've used for years simply aren't needed anymore.

And as for the missing pieces... well, what can we expect from a loosely typed language that was famously created in about a week? 😂

𝕋𝕙𝕖 𝕃𝕒𝕫𝕪 𝔾𝕚𝕣𝕝 • Jun 24

Wow, absolutely loved this breakdown! JavaScript is evolving so beautifully, and these ES2026 features are exactly what we needed. Map.prototype.getOrInsert() is an absolute game-changer for reducing boilerplate and boilerplate map checks, and the performance benefits of Iterator.concat() without memory bloat are huge. Love the witty examples and the tone of the article—makes complex updates so digestible and fun to read. Can't wait to start refactoring my code with these. Thanks for this amazing write-up!!!!

Sylwia Laskowska • Jun 24

Thank you so much! 😊

That's exactly the goal: raising awareness of what's already available in the language, so people don't end up pulling in entire libraries for things JavaScript can now do out of the box. 😄

And honestly, some of these additions may look small, but over time they can remove a surprising amount of boilerplate from our codebases.