>And what it “gains you” is never having to think about something changing in a way that produces invalid or unexpected state. (This is more true in statically

>And what it “gains you” is never having to think about something changing in a way that produces invalid or unexpected state. (This is more true in statically typed languages of course.) I think it's more accurate to say that it makes you account for the possibility that an object is put into an invalid state at every mutation you do. Which can be good and can be bad. Good being that your code is safer and less likely to have errors. Bad because it's more rigid and trickier to deal with objects containing multiple errors.