Hey is a knife considered a weapon like can you have it in your car?

because we do live in north carolina but am going to pennsylvania to bring my sister home and i was wondering if we get stopped by the cops and there is a pocket knife in the car can you get arrested because we will be stopping at a hotel and i dont want to get robbed so i wanna bring a pockey knife so is it illegal in west virginia virgina or pennslyvania to have a pocket knife in a car or on you because we r leavign omorrow thank yu