Can a hidden creature attack an unsuspecting target before combat begins?

@JeremyECrawford Can a hidden creature attack an unsuspecting target before combat begins?

— Camellia Kitasake (@CKCamellia) November 18, 2015

Outside combat, you roll initiative if you declare an attack against a foe. You then take action on your turn. #DnD https://t.co/HJjBaKm2Ok

— Jeremy Crawford (@JeremyECrawford) December 4, 2015

@imnotasnowflake @CKCamelliaif a creature is surprised, they don’t get an action though, correct? A surprised creature wastes its turn being surprised, since it can't take an action.

— Jeremy Crawford (@JeremyECrawford) December 4, 2015