Enthuware

If 'number' is null, then won't number.length() == 10 throw a NullPointerException? Which would be another reason why this code will not work in all situations if assertions are enabled? And would that make the code syntactically incorrect? Or does this have nothing to do with syntactical correctness?

public void processPhoneNumber(String number) {
assert number != null && number.length() == 10 : "Invalid phone number"; ... }

Thanks

Since && is a short circuiting operator, if number is null, number.length() part of the expression will not be executed.

Thanks for replying. But is that syntactically correct? I'm guessing you think it is.

Yes, it is syntactically correct. No compilation error.
You can actually try it out with a simple test program.