Throwing exception vs returning null value with switch statement

Question

So I have function that formats a date to coerce to given enum DateType{CURRENT, START, END} what would be the best way to handling return value with cases that use switch stat

Answer 1

I think that throw new IllegalArgumentException("Something strange happend") is the best pratice.

Using null will just presumibly cause a NullPointerException somewhere when you use the return value but it will be less informative than raising a specific exception that describes the problem!

And you know: clear errors = better developing.