As a Web developer? A lot of languages out there but I want to study something that's lucrative and marketable.<p>I'm thinking of leaning towards becoming a Full stack Javascript guy but not sure about the salary and demand for the language.
It really depends on the company and market location you're in. Around here (SF / Silicon Valley), there are tons of companies hiring Ruby devs. So if you're around here, that's probably the route to go.<p>If you are interested in Enterprise, Java is probably still dominant.<p>JavaScript is a must for front end stuff but I can't say that a lot of companies will adopt it heavily for backend, particularly if most are already established on some stack they've already been working on.<p>My best recommendation without knowing much is go with Ruby and Rails.
Startups - Everything really. There's lots of JS and Python, but by definition they aren't very lucrative because startups don't have much money (ignoring <i>potential</i> future earnings).<p>Agency - Mostly PHP still but knowledge of Node is good (mostly for tools like Gulp). Occasionally see Ruby and Python in more design oriented agencies. Money is ok, and there's <i>a lot</i> of work out there.<p>Corporate - .NET, Java are all relatively popular. Java gets the best money because it's used extensively in the finance industry.
I work with a lot of programmers and the ones that bang out a ton of small projects are the ones I see earning the most money (or the ones that I give the most money to)<p>PHP/Python programmers with a sound understanding of JS/HTML/CSS and a familiarity with basic networking protocols that also have their wits about them in terms of basic UX/UI is the magic recipe that I am constantly looking for.
I think you should focus on programming itself and learn how the compiler works also master one of version control systems. Once you understand the idea behind the programming languages, it's easy to understand different languages. As people said, 10 years from now, your best language may be out of date but the basics will be same.
As a long-time developer, I can tell you that, no matter what you choose, ten years from now, it will be out of date. That means you should focus on robust, transferable skills like basic computer science knowledge that applies equally to all languages and environments.