I was just re-reading Chamber of Secrets....I remember in Prisoner of Azkaban at the end where they keep talking about how it is impossible to apparate and disapparate in Hogwarts. However, at the end of Chamber of Secrets, Dobby disapparates.....is it only witches and wizards who cannot, or did J.K.Rowling make a mistake?
If this has been answered before, I apologize, my memory isn't the best....and I may not have seen the previous answer.