What language should a beginner learn in 2017 to find jobs easily?

Can you explain the distinction, the pros and cons; in a simple to understand way, for Controlled Components vs. Uncontrolled Components?

I’m looking to gather a set of guidelines one should keep in mind while building my React components; what are the times when I should be making it a controlled component, and why? To ask a question further; how should I be managing controlled compon...