Improve .forEach examples: syntax and consistency

[tshemsedinov]

Summary

• Change var and let to const where possible
• Use == instead of ===
• Use one-line arrow functions is possible
• Improve code indentation and alignment, fix other style consistency issues

Motivation

To refresh code examples before making changes to the article itself.

Metadata

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

[github-actions]

Preview URLs

• https://pr12799.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach

Flaws

None! 🎉

External URLs

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach
Title: Array.prototype.forEach()
on GitHub

No new external URLs

(this comment was updated 2022-02-07 21:15:23.935225)

[danielhjacobs]

I think this == null is accurate based on the wording "Array.prototype.forEach called on null or undefined", since this === null won't be true for undefined. I've heard == null described as the only good reason to use non-strict equality in JavaScript. If you prefer to never use ==, that's fine, but then you should probably change to this === null || this === undefined

[wbamberg]

Thanks! These generally seem like good improvements but I had a couple of suggestions.

[wbamberg]

I think we should delete this whole "Polyfill" section. We already link to a polyfill in "See also" and we have a general consensus that we don't want to embed polyfills in MDN pages: openwebdocs/project#27.

[tshemsedinov]

Removed in separate commit, just don't cherry-pick it on landing it it should be a separate PR

[wbamberg]

👍 thank you @tshemsedinov !