What's New in JavaScript for 2019

What’s New in JavaScript for 2019

Here are the new features coming to ES2019 for JavaScript.

Zibri (http://www.zibri.org)

What will make Javascript take a huge leap forward will be a proper standardized compiler like gcc.

Jēkabs Kārkliņš

Definitely private and public function access modifiers would be awesome. And without hash in front of them. I see how that would make it easier to spot private function in code, but as long as you have private in front of function, good IDE can do the rest by coloring, underlining or whatever developer him/herself prefer.


I’m agree for private tag…


I would love to understand why the f*** the hashtag is prefered over a simple private keyword. Why use static then ? let’s prefer something like ‘@’ to mark static …
is it because JS is to good to use well established standard ?

I’m not gonna drop Typescript anytime soon …

David Neal

There is an explanation on the thoughts behind the hashtag syntax.

David Neal

Here are the current reasons behind using the hashtag symbol. Something to keep in mind, is JavaScript is a dynamic language, and types can be added/modified at runtime, so that does complicate things.


when you stop to think about it, and put yourself in the shoes of the guy in charge to add private attributes. You might not like it. But given the current lang limitations whoever came with the idea of using # is a genius (it’s the easiest, shorter way to do it imaginable).


While I understand the reasoning I also think it’s so ugly. And at what point will this become brainfuck? Maybe it’s time to design a new language, or adopt typescript in the browser?

Hannad Ur Rehman

classes are a debate


What other ways would you use to signal it’s a private field/method/…?

Fabio Roldan

It would be interesting to use UML + public - private # protected

Nikhil Jauhari

I do agree for private way, # make it looking a bit strange.

Filipe Costa

No… we should NOT put ourselves in the shoes of the guy who’s introducing this syntax. we should put ourselves in the shoes of daily Javascript users.
I guess you should be more worried with the Javascript community feedback and Javascript language future then trying to introduce this non-loved syntax at all cost.

The class introduction was a mess…
Now you want to introduce the traditional line comment as a private field identifier (?!)
Tomorrow you’ll just kill Javascript.

Rafael Corrêa Gomes ♛

Thank you for sharing!

Dmytro Pylypenko

Thanks for the article.

Private declaration by hash symbol # is a terrible part, wonder why it’s almost accepted instead of underscore _.


almost certainly because of the widespread use of lodash and underscorejs libraries which use the _

Dmytro Pylypenko


There is big difference between _.something and this._something.

daniel barde

I think the hash is better off compared to the “" because "” is a valid character in a variable name. Also, they might have been looking for something to easily differentiate the private props from the public. Wonder why a private keyword didn’t come to mind though like in other languages.

Dmytro Pylypenko

I see your point, it makes sense, to use reserved character.
But obviously private keyword gives more flexibility.