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Comment by detaro | Hacker News Reader

Since linked lists are a concept you don't need in many languages, I don't think you can nowadays say someone not knowing about them is "not a developer". They are a developer without knowledge of some fundamentals, but they can be perfectly productive as a developer without that knowledge.

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He doesn't know what a linked list is? Srsly?

Yes, seriously. If someone learns programming with JS (or Python or ...) and has neither been interested in nor exposed through work to lower levels they can easily go years of professional work without having to deal with the concept (not meaning that they wouldn't understand it, just that it never came up). Thanks to abstraction, you can go far without really knowing what's happening below, and that has moved up the layers more and more.

Where does a JS frontend developer really need to have heard of linked lists?

JS and Python can't decide what's best for your problem: an array or a linked list. It's the programmer who decides these things. I'm currently working on a project started by people who apparently were completely unaware (among other intellectual obscenities) that it's not OK to return a long list of integers by concatenating them into a long string only to split and parse them again later when some subset of this list was needed. Recently, due to increased traffic, the web service kept crashing.. with 64GB of RAM. Some of these people are probably on this forum, trying to justify why "you can be productive" without knowing wtf you are actually doing.

To be fair, languages like Ruby and Javascript only have one sequence container in their standard lib and the difference just doesn't come up for most people most of the time. Just like how most day-to-day data for most people probably fits in array with a capacity <100. And the most common day-to-day operations are array[0] and array.append().

And even when it's thrown in your face like listOf() vs arrayOf() in Kotlin or [] vs '() in Clojure, one is the conventional default that you use most of the time anyways.

That said, someone who doesn't know what a linked list may also be lacking experience with many other things that you would expect from a candidate, but it's no mystery how someone can go far without really encountering one.

The reason almost any developer should have heard of linked lists is that understanding them is fairly fundamental to understanding a bunch of other useful data structures.

Some of it may be a terminology problem as well - frontend devs may not have met "linked lists" but what's the difference between a doubly linked list and a straight series of nested objects where no object has more than one child?

He clearly lacks depth if he doesn't know how JavaScript works...

Sure, the question is if that lack of depth actually matters. It certainly doesn't make a designer out of someone.

What do you mean by "know how Javascript works"?

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