Upgrading to the latest version of Ionic

Hi all,

This may seem a silly question, however I can’t find an answer to my question.

I basically want to create a new app using the latest version (Ionic 5). If I upgrade my version of Ionic to the latest version (5), I’m currently on (4), will my existing projects still work which are built in older versions of Ionic? or am I going to have loads of build problems?