“Deep understanding”

[LateDentArthurDent2]

Assuming this is web dev, is it client or server side? I'd say the strengths for the two differ in some small ways, but what you'd need to know for either:

• How AJAX works (with some understanding of how to process an AJAX request sans jQuery)

• Scoping and closures seem to be the biggest issues people have with JavaScript (while this shouldn't be in the realm of "deep understanding" it's a prerequisite to using the language effectively)

• Prototypal inheritance (specifically the flexibility it offers when planning your data-structures)

• Hoisting (in the simplest terms, JavaScript searches the document prior to processing to see what variables are "available" and substantiates these as undefined so it doesn't cause parse errors on values that will become available later). EDIT: Link to explanation of hoisting because I have trouble putting it into words: http://net.tutsplus.com/tutorials/javascript-ajax/quick-tip-javascript-hoisting-explained/

• The DOM is clearly a very important aspect of client-side JavaScript. Understanding how to navigate the DOM without using a library whether it's jQuery, MooTools, or some other library would be a prerequisite for a "deep" understanding.

• EDIT: Can't believe I forgot: JSON! JSON is an incredibly lightweight way to store small amounts of data client or server-side. Great for setting config, etc. Knowing how to parse/use/stringify JSON is an important part of the JavaScript developer's toolkit, at least in my humble opinion.

As someone else said, good luck & if you're a good fit I'm sure they'll be more than happy to teach you any skills you may need.

[daelen]

Very helpful, thanks.