Null values don't go away, it's just that reference types aren't by default nullable. Your function can still return null (if you really want it to) as long as

Null values don't go away, it's just that reference types aren't by default nullable. Your function can still return null (if you really want it to) as long as that is indicated by the return type. What you can't do is directly assign the possibly null return value of your function to a non-nullable reference.