What features of the JavaScript language should I pay attention to when learning it after C#?

Question

JavaScript

I have been working as a .Net developer for about five years, sometimes I had to develop web faces in Angular, but I don’t have deep knowledge of pure JS. Now I'm thinking to study JavaScript and Node.js more deeply. I would like to find out what things and features of this language should first of all be paid special attention to when switching from C# to JS. Other than the obvious dynamic typing, of course.

Answer 1

Features with closures and this, prototypes instead of classes, and type casting in places can surprise, yeah.