Do javascript developers need to know jquery?

Question

If you were to hire a javascript developer would you expect them to know jquery?

I just started using stack overflow this week and knew that jquery led the pack, but didn't realize the extent of it until I noticed that MooTools (my favorite) has 59 questions while jquery has over 4000. (of course, a good statistician could attribute jquery having more questions to it's usability, rather than it's popularity--but we know that's false)

And then I started noticing that many people post questions with the tag "javascript" but not "jquery" when every line of their code is jquery--like it's the de facto javascript 2.0, or that they don't even realize they aren't writing "javascript" but rather jquery.

Anyway, I ask this because I've always been freelance and could use whatever framework I want on a project. But lately I've been recommended to be the front-end developer for a couple companies. I want a feel for the community's expectations to know if I should put some other personal projects on hold to pick up jquery before exploring the positions that might be offered.

Answer 1

No. I'd expect them to know how JS works. A good JS developer will pick up jQuery in less than a week, probably a few hours.

A developer who knows jQuery but doesn't know JS has a great deal to learn and would only be considered for the most junior roles.

jQuery is definitely not JS2.0 - it's a great standardisation framework if you still need to target IE8 and the like, but it's not great at mobile, it can't be loaded with async or defer, it doesn't support newer features like passive events, and its primary optimisations are about finding elements in an already built DOM (which means it doesn't add much value for client side DOM builders).

I would expect them to have heard of it, and be able to talk about its strengths and weaknesses against other frameworks.

Answer 2

They should at least know what JQuery is, and be able to tell why they chose it or another framework. Next to that, a basic understanding of the most popular javascript framework can never hurt.