How to add animation to addClass?

Question

css

Hello. I have a question when creating a calculator. How to animate addClass and removeClass? Through css does not work at all. For some reason it doesn't work through jquery ui either. Who can submit a decision? Preferably with an example) Thank you in advance)

Answer 1

If you want that when adding / removing a class for which styles are written, these styles are applied / removed animatedly (smoothly), just set transition in css to this element.
If I misunderstood you, correct me, or reformulate the question.