Update "Working with objects"

[alattalatta]

Summary

Fixed and updated the doc here and there.

Motivation

• Code blocks don't comply MDN code formatting rules, such as missing semi and things.
• Code uses var, changed to let and const.
  • Didn't use const to avoid having to explain here why a const object properties can be changed... Which I think can be confusing. 🤔
• A few sentences are out of its place, such as line 156. (upstream)
• Some links are outdated.

Supporting details

Related issues

Metadata

• Adds a new document
• Rewrites (or significantly expands) a document
• Fixes a typo, bug, or other error

[github-actions]

Preview URLs

• https://pr10724.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Guide/Working_with_Objects

Flaws

URL: /en-US/docs/Web/JavaScript/Guide/Working_with_Objects
Title: Working with objects
on GitHub
Flaw count: 1

• broken_links:
  • No need for the pathname in anchor links if it's the same page

External URLs

URL: /en-US/docs/Web/JavaScript/Guide/Working_with_Objects
Title: Working with objects
on GitHub

No new external URLs

(this comment was updated 2021-11-24 02:38:15.023221)

[wbamberg]

Thanks @alattalatta , this is a good improvement!

I had one very minor comment. I would merge this PR even without it being addressed but please accept it if you agree. On this:

• Didn't use const to avoid having to explain here why a const object properties can be changed... Which I think can be confusing. 🤔

I agree that const can be confusing, mostly because it is badly taught. For that reason I think it's important to use it consistently in our docs and explain it clearly from the start.

We discussed this issue recently: https://github.com/mdn/content/discussions/10389 and agreed to use const in situations like this.

But I'd merge this PR anyway because it's much better than what was there before.

[wbamberg]

Very nice cleanup. Thank you @alattalatta !