My friend told me his dad hit him and then he told me he was joking. Is he really...

How long have you known him? Did you give him a serious look after he said, "oh I'm kidding!" or did you laugh along with him? Did he ever joke like this before? If you know him well - just tell him that you care about him and you took his statement seriously (and go on from there).

Its ok if ur dad hit or slap you because its good for you and dont become sick all father wants his son to become good person with good behaviour ..