jQuery is a brilliant tool for manipulating the DOM and for managing AJAX calls etc. etc.<p>However you can't truly master jQuery without also developing a thorough understanding on JavaScript. The alternative would be to construct a hodge podge of jQuery plugins and widgets to get things done - and then running into all the limitations, conflicts and outright bugs they will bring with them. [I have borrowed from such sources but have always needed to modify the code]. Much better to be able to write clear straightforward code of your own in JS - taking advantage of jQuery when it is an advantage of course.<p>Apart from anything else JS is a delight and learning how to use it will develop your programming skills.
It's not bad. jQuery is a JavaScript library and you'll learn JS as you go. It's only bad if you fall into the stereotype of not caring and just copy/pasting jQuery snippets from Stack Overflow.
I am in this position right now as I am working on a startup in my free time. I've been coding the backend API in Flask but I am delaying the frontend due to a lack of JS knowledge. There are plenty of jQuery examples but sometimes I have no idea what I am looking at or how the code is flowing. My lack of JS skills will probably introduce security risks into my website.<p>So I am now forcing myself to start working on some basic JS tutorials and my friend recommended I pick up this book: jQuery: Novice to Ninja: New Kicks And Tricks.
It really depends. I would say it is bad if you want to claim mastery of JS.<p>However, I all the time need to get things done using tools like jQuery, underscore.js, async etc ... These libraries make my work so much easier and I don't necessarily understand the internals of their working.<p>Things seem to working fine so far and my knowledge of the fundamentals keeps on improving as I work. That works just fine for what I am trying to accomplish.
As others have mentioned, it's impossible to "master" jQuery without a very solid understanding of JavaScript. You'll end up with code that does way more work than it needs to, and is way sloppier than it should be. I'm pretty certain that mastery is impossible without an understanding of the foundation and the abstractions.
Pretty bad if you plan on employing lots of JS in the long run. As fantastic as jQuery is, when it's all you know, everything looks like a $-shaped nail.<p>That said, you don't need to go crazy and go off it cold turkey, you can very much expand your JS knowledge while using jQuery still for day to day AJAXy and DOM manipulation tasks.
Might not call it bad, but you should really also learn JS - as brilliant as jQuery is, it can't really do everything.
It's also much better to know js in order to debug stuff that misbehave (you can also download the un-minified jQuery code and just step into to it ... can save a few hairs off your head)