When handing in ur 2 weeks notice, do u let them know what company you’ll be moving to?

No

Why would it matter?

No you dont it non of their business they can sabotage your new place

@codePain happened to me almost. I went working for company next door and they called that company and are like 'WTF'. That company didn't want a fight and I was really worried that I left one company and the other one didn't want to hire me anymore.

Well, i would always tell it my close coworkers. That's called being social I guess. Also, you can say smth like "A company in the automotive sector", and with that answer they know that you don't want to specify which one exactly.