Concepts to help developers master JavaScript

https://github.com/leonardomso/33-js-concepts

by alexgrcs • 8 years ago

316 51 8 years ago

github.com

vorticalbox• 8 years ago

This has been posted at my work, it's a very good resource.

z3t42• 8 years ago

What got me to love JS was probably learning about variable scope, closures, and async programming.

pdpi• 8 years ago

As opposed to what other language?

soneca• 8 years ago

Maybe not opposed to any language.

afandian2• 8 years ago

Not GP but variable scope in JS is very different to e.g. C, C#, Java etc. Superficially it appears similar, but the syntax is a faux amis.

geezerjay4• 8 years ago

Those features are hardly exclusive to javascript. Why did they made you love javascript but not any of the myriad of languages that support those features?

tw1010• 8 years ago

What makes you assume z3t4 exhaustively tried every other language before settling on JS? It's not typical that you present your opinion of a tv show by giving the few unique positive traits it has in contrast to the union of all positive traits from tv shows in the same genre. You just watch the show on a micro level, record what you liked about it, and report that, regardless of what the macro landscape looks like. That's the same way coders typically report preference about languages (on a micro level, not a macro level).

z3t42• 8 years ago

Embarrassingly enough I had programmed for many years before understanding those concepts. I only knew them instinctively. Coming from a multi-threaded web framework background, writing heavily async code was painful. But it became so simple after learning about closures and lexical scope, and that's why I consider them to be JavaScript's main features, even though almost all other languages have them too. The main reason why I haven't moved on to another language is that I get PTSD (from maintaining multi threaded code with global variables) - when I see a variable or function that I don't know where it comes from, which is common in languages that does not support lexical scoped named imports.

weliketocode• 8 years ago

I wouldn't say love, but I certainly now hold a stronger appreciation of JS after learning about many of its quirks and intricacies.

epicide4• 8 years ago

This is what I try to convey to a lot of people who keep making jokes about JavaScript being unpredictable and hard to program.

Just like everything else (especially programming languages), you are limited by your understanding of the concepts. It's only as difficult as you make it.

I think so many people think of it as a toy, never bother to actually learn how it works, and assume everything either does or should work like it does in other languages.

tome• 8 years ago

It's only as difficult as you make it.

Or as difficult as the authors of the code you're using made it.

vinceguidry3• 8 years ago

We're migrating an app from Ruby to NodeJS, and I keep hoping it'll get better, but everywhere I look, from the inconsistency and constant shifting of language semantics to the immaturity of the ecosystem, and how the former practically enshrines the latter, I can confidently state that Javascript is an objectively worse language. Attempts to solve problems caused by Javascript only make the whole thing worse.

At the moment, I actually prefer vanilla javascript to ES6-7. ES6 is inconsistent in awful ways. You still can't rely on bindings to stay put and new additions like the splat operator just don't work the same way all the time.

The more I learn JS, the more I hate it. I think eventually the web development community will come around, Node will lose mindshare, and compile-to-js languages will find their place in the sun again.

I suspect that people who actually like the language are experiencing a form of Stockholm Syndrome.

gmiller123456• 8 years ago

you are limited by your understanding of the concepts. It's only as difficult as you make it.

I disagree. It is very possible to understand a concept fully, but for it still to be hard. E.g. pointers are quite easy to grasp the concept of, but also very easy to mess up. A more related example would be JavaScript's type coercion. Just understanding it, doesn't make it easy to avoid overlooking places it will cause problems. So some features programming languages include can be objectively considered harder than others, even when you fully understand them.

sonnyblarney• 8 years ago

"Just like everything else (especially programming languages), you are limited by your understanding of the concepts. It's only as difficult as you make it."

No - JS is a special beast. Because it's designed from a simple hack on up, by distributed committee, with so many implementations ...

it's inherently problematic.

Foremost - when you say 'JavaScript' what does that even mean? Even different JS versions are implemented slightly differently with some containing features, others not.

It's this tedious, byzantine aspect of JS that makes learning it actually hard, because it's like walking on shifting sand.

At least with Java (and most other languages), there is usually one answer however bad or good, usually you know where you stand.

yoerivw• 8 years ago

Thank you for posting

ArtWomb• 8 years ago

Really good list. Deserves a section on performance and debug tools as well: cpu and memory profiling, high res timers, requestAnimationFrame, etc.

zachrose2• 8 years ago

One intuition I’ve had while learning Elm is that it’s a fundamentally simpler language with a smaller number of concepts to learn than JavaScript.

In this list of 33 JavaScript concepts, I count 11 that either do not exist in Elm or, like Object.assign, do not have an alternative to worry about:

No reference types

No type coercion

No == vs ===, although typeof has a simpler equivalent

Basically all expressions and no statements

No hoisting as such

No prototypical inheritance or prototype chain

No Object.create, no destructive alternative to Object.assign

No factories or classes as such

No inheritance or polymorphism

No design patterns as such, though you could argue that abstract algebra or category theory are the replacements

No this, call, bind, or apply

The finer points of these are somewhat debatable, but overall my contention is that removing mutation and local state makes a lot of related concepts just fall away. A takeaway is that when someone tells you that they’ve learned Elm, you needn’t assume that this was as huge of an undertaking as learning JavaScript.

k__• 8 years ago

You don't need all of these concepts on an everyday basis.

If you don't use ES5 stuff that was replaced in newer versions, things get much simpler.

let, =>, === etc.

technion• 8 years ago

Despite the submitted title containing "to help developers master", the actual Github page title contains "every JavaScript developer should know."

I think that casts this post in a different light. If the repo's intent is that "every JS developer should know" everything on this list, the context of this discussion changes.

_greim_2• 8 years ago

One thing I've found with functional programming (Elm) is that writing JS requires constant mental effort. E.g. dynamic types, mutations, side effects, state. In Elm all of that neural machinery becomes obsolete, but your brain doesn't just magically switch it off. So Elm feels hard at first, until the concepts sink in a little bit and your brain re-wires itself.

zachrose2• 8 years ago

Yes, this very much describes my experience of working on a gigantic Backbone app while using Elm at home. Work has gotten harder because I’m (rightfully) paranoid about mutation and unable to trust the (fallible) conventions of OO JavaScript.

sridca• 8 years ago

And then you move to Haskell from Elm.

https://haskell-miso.org/

https://reflex-frp.org/

dan-robertson• 8 years ago

No == vs ===, although typeof has a simpler equivalent

Sure, but elm has its own issues with comparison as these are essentially implemented as a compiler hack, and only comparable (ie primitive or lists/tulles thereof) types can be used as keys for the built in map type (so you need to know about primitive types too)

tabtab• 8 years ago

I'm sorry, but any language that has to rely on "===" to know what's in what is usually fundamentally screwed up. (Yes, I'll probably get downvoted for this. Oh well, truth often ain't popular.)

nottorp• 8 years ago

This looks like a bunch of generic programming resources. Possibly with implementations in javascript.

I clicked in hope I'll get something targeted towards developers that have nothing to do with the javascript "ecosystem" but understand programming concepts, algorithms etc. Is there such a thing?

sugerman• 8 years ago

IMO, these collection of links type resources would be much more useful if the author curated the list down to something like "Read This_Article for This_Topic" and let people then just google for more information if they need it. Just googling and inserting the top 10 links into a list isn't adding much value.

waveforms• 8 years ago

I have to mention Dmitry Soshnikov's "JavaScript. The Core" webpage. The concepts explained in version one published in 2010 helped me land several contracts. Now I see he has "JavaScript. The Core: 2nd Edition". Thank you Dmitry!

http://dmitrysoshnikov.com/ecmascript/javascript-the-core-2n...

_greim_2• 8 years ago

Disappointed that there's no top-level section on iteration. It's a powerful but under-utilized part of the language.

crescentfresh• 8 years ago

I wish everything on this list fell under the "JavaScript" umbrella, but really they're all conditional on which version of "JavaScript" you're trying to master. Eg "vanilla" js, ES5, ES6, etc. So it's hard to know what came when and what you can actually use in the project you might be working in/creating.

Concepts to help developers master JavaScript

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