UIUC Transfer Student - Can I Double Major?

I recently got into UIUC for economics, and I am considering transferring next fall as a junior. However, at my current college, I’ve been taking computer science classes that I have been enjoying immensely. Is it possible to declare a double major as a junior transfer student or even just switch my major to computer science?

I’m aware that there’s a distinction between computer science in the Liberal Arts College and the College of Engineering (which is more competitive). I would want a double major in Computer Science - Statistics in LAS.

It’s really hard to transfer into any of the CS majors, even the LAS ones (Math+CS and CS+Stats are basically as competitive as CS Eng since they’re so popular). This applies for trying to double major in it as well.

Also, I don’t know if your current classes would transfer - something to ask an advisor about. If they don’t cover the first two years of CS classes, which you need in order to get the CS major, then it’ll be hard for you to finish the major in two year (assuming you even get a spot in all the classes you need).