For my students, why are you learning to code? Is it just because the school says so for your thesis?
What are you interested in doing? Producing animations that include characters, fancy drawing and game play? Or just text and interface based animations for a text and still photos site? Is your thesis project going to be an app, a responsive site or a dedicated mobile site?
The field is going towards JavaScript, my assumption is in five years almost everything will start with html, css and Javascript and then build in some way or form on that. HTML is just a cockroach that survives. You need to know it cold no matter what.
But animation and game based work is currently a lot easier to do in Flash right now, it’s what Flash started life as and publishing to devices is just easier from it. If you have Android you can do it now as easily as making a swf, Apple makes life harder because Apple (*&*^*&%!!!!****).
Ultimately the reason anyone other then computer scientists should learn to code is that it builds the logic of interactivity into your bones. When you have to make something work you have to pull the problem apart until it reaches it’s smallest unit which you can make. You then have to learn how to assemble blocks into a larger project which is how the pyramids, Rome and everything else was built. So learning to code even if you go become just a UX designer or information architect is important because you know what the tools are that your projects are built with.
Business wise having JS skills makes you much more valuable these days and from that perspective it’s hard to say don’t build it in Flash. But if you have a cool creative idea that is fresh and interesting people will hire you because your smart and do cool things. Since ActionScript and JavaScript are from the same family all of your skills and knowledge will transfer over. Do interesting things with interesting thoughts and no one will care at all what tools you use.