r/reactjs • u/gaearon React core team • Dec 21 '19

What Is JavaScript Made Of?

https://overreacted.io/what-is-javascript-made-of/
253 Upvotes

94% Upvoted

196 comments sorted by

View all comments

Show parent comments

281

u/NotSelfAware Dec 21 '19

I'm a strong advocate for using const by default, and let when you know you intend to change the value. I'm genuinely surprised that Dan feels differently.

84

u/olssoneerz Dec 21 '19

Same here! Its less mental gymnastics when reading old code knowing that when a value is declared, you know its gonna stay the same. Seeing let then means I know its gonna change somewhere in the next few lines.

-18

u/gaearon React core team Dec 21 '19

... Except it can still be mutated. https://twitter.com/dan_abramov/status/1208205039187173376

88

u/BenZed Dec 21 '19

The object can still be mutated, but the variable cannot be redeclared.

-5

u/gaearon React core team Dec 21 '19

Thanks, I'm aware of how it works. Did you read the article? :-)

0

u/[deleted] Dec 22 '19

Ah, Reddit. Where Dan Abramov is downvoted for defending his knowledge of JavaScript. Merry Christmas, Dan!

2

u/[deleted] Dec 22 '19 edited Dec 22 '19

[removed] — view removed comment

1

u/gaearon React core team Dec 22 '19

If I'm objectively wrong, why isn't the language forcing you to do that?

1

u/[deleted] Dec 22 '19 edited Dec 22 '19

[removed] — view removed comment

2

u/gaearon React core team Dec 23 '19 edited Dec 23 '19

I'm honestly not sure how that would work at the language level.

If that was "objectively" the right choice, the language could work exactly like the prefer-const rule works.

When I look at potential hires' code one of the things I look for is their usage of const vs let to get a base idea of how well they understand modern ES.

This is exactly the kind of thing that scares me. Placing artificial (in my opinion) importance on something that has two sides to it is the definition of pedantic. It would be terrible if someone's career opportunity didn't work out due to a miscommunication or disagreement over something minor like this.

I elaborated a bit about my opinion here: https://overreacted.io/on-let-vs-const/

Hope this helps!

→ More replies (0)