I've applied for a junior development role, or rather been found by a recruiter looking for a developer. In order to get to a telephone interview stage I've been asked to sit one of those online coding assessments.

This wasn't quite what I expected. I consider myself a fairly good developer for my age and experience, but I've no illusions about being Don Knuth or anything. The test was a series of incredibly obtuse questions asking about the results of various obscure evaluations. About 30 minutes in I was thinking to myself I hadn't intended to enter an obfuscated code contest/code golf exercise.

After my last telephone interview I was asked to build something. I did. That seemed fair. Go away and work this out is more my in office experience of programming than "please evaluate this combination of lambdas, filters, maps, lists, tuples etc".

So I'm a little put off, to be honest. I never claimed to know the language inside out or all the little corner cases. My questions, then:

1. Should I be put off? Why? Why not?
2. Are these kinds of tests what I should be expecting for junior roles?
3. Should I learn stuff exam style? That seems to be the objective of these tests, for which you are timed and not supposed to use references or books? Normally, in the course of development I have a fairly good idea of basic types, rules, flow control and whatever. Occasionally I'll come up on something I need to use a regex for and have to go and remind myself of the exact piece of syntax I need if trying what I think should work doesn't. Or I'll come up against a module I've not used before and go and look it up. For example, if I wanted to write a server using sockets in C right now, I'd probably check the last piece of code I wrote doing that (and or the various books I have) and work from there. Chances are I probably couldn't do it exactly from scratch and from memory, although I can tell you you'd need a socket(), bind(), listen() and accept() call and you might also want select() depending on whether you intend to pthread_create or not. So I know what the calls are, but not their specific parameter list.
4. What are your experiences if you are a recruiting manager? Are you after programmers who can quote you the API or do you not mind if your programmers have a few books on their desk and google function calls every so often?