Oh no! It's already out of date! (That's a JS changes too fast joke)
But seriously, calling it 'modern' is pointless. It's not adding anything valuable and its just going to become out of date (and thus wrong).
But seriously, calling it 'modern' is pointless. It's not adding anything valuable and its just going to become out of date (and thus wrong).
The guide might come to lack some newer things over time, but I doubt those will include any major paradigm shifts, because the past ~10 years have likely been the most dynamic that JS will ever see in terms of idioms and best-practices. JS made a radical shift into a mature language, and now it is mostly on the other side of that transition. So writing a "modern" (post-transition) tutorial makes perfect sense to me, and I don't think it will become irrelevant any time soon.
Can you help me debug why `document.createElement('button').attachEvent('onclick', e=>alert('attachEvent!'))` isn't working then?
You might object that DOM APIs aren't part of JS proper and that's true, but this guide covers `addEventListener` on this page: https://javascript.info/introduction-browser-events
Sticking only to JS language features, I assume you can help track down why my `with()` statement doesn't work. Or why `function testing() { console.log(this.location.href); } testing();` throws an error but only if I package my code as an ES Module instead of an AMD bundle.
I agree that breaking changes like this are increasingly unlikely to happen, and I think the changes that have been made are easily net positive. But the claim that they never happen is simply not true.
I'll refine my statement to "The JS standard never introduces breaking changes".
attachEvent never was part of any standard, and is therefore subject to breakage. Non-standard APIs should never be part of a comprehensive guide to the language in the first place.
The `with` statement is described on page 75 of the ES3 standard[0]. It does not work in an ES Module or in a strict mode context. This is a breaking change.
But when most people say "breaking changes" they mean things that suddenly cause legacy code to stop working, and non-strict mode will almost certainly be supported ad infinitum, so I don't really count that. It's also almost certainly never going to happen again.
OTOH out of scope are server-side JS (NodeJS), transpilers like babel, bundlers like webpack, and of course package managers like npm and yarn
- for in loop - for of loop
as a couple examples, and those have been around for at least a few years now. There's probably more missing too. To what the above person said. The usage of "modern" or "latest" or similar is going to fall behind and make for bad searching.
It's 2020 and you still use loops? ;-)
That eslint rule is a good example of a cargo cult. The second link in its rationalization argues for using underscore over touching a dangerous loop yourself.