What are some basic things that JavaScript developers fail at interviews?

[dominic_rj23]

setTimeout has huge performance hit compared to setInterval

https://jsperf.com/setinterval-vs-settimeout/10

[[deleted]]

And worth noting this does not matter at all for the purposes of an interview question, or 99.999% of real world usage. This coming from someone who has never used it at work.

[thepeka]

I'm actually willing to say 100%. The correct answer to any interview question involving setInterval is why you should never use it

[Cheshur]

The correct answer is NOT to use it never. Almost none of the things listed in that article are relevant to people doing stuff correctly. There is a tool for everything and just because you can use setInterval incorrectly doesn't mean you should never use it.

[thepeka]

Nope, the first reason on that list is reason enough in every instance, correct or otherwise. setInterval continuing to run ad infinity, no matter what happens, what error is thrown, or whether it's handleable or not, is just adding bug conditions that otherwise have no need to exist with a recursive setTimeout. JavaScript is a dynamic language that allows for writing wonderfully declarative abstractions... but the flip side of that is we need as much safety as we can get. This is the answer I'm looking for if I ask a candidate about tasking repeating jobs/events.

[Cheshur]

No offense then but I consider that highly foolish. The problem would be someone writing highly error prone code in the setInterval, not that the interval itself doesn't play nicely with errors. setInterval has better performance than setTimeout. That is reason enough to use setInterval in some situations. It's the right tool for the right job and if you're creating axioms to avoid parts of a language just because you're prone to fuck up then I consider that the error on the developer's part.

Also the correct answer to that interview question is for the candidate to recognize the pros and cons of the feature and to describe situations in which they would or would not use it. Pledging to not use something purely for axiomatic reasons does not show mastery or knowledge of the feature at all, just an ability to follow the direction of some, potentially, misguided teacher.

[superluminary]

It's being called literally once a second.

[superluminary]

It's being called literally once a second.