listing continued while(current ddata !keycurrent current nextif(current =nullreturn nullif(current==firstfirst current nextelse /until match is found/move to next link /didn' find it /found itfirst item/first --old next /not first /old previous --old next current previous next current nextif(current==lastlast current previouselse /last item/old previous <-last /not last /old previous <-old next current next previous current previousreturn current/return value /public void displayforward(system out print("list (first-->last)")link current first/start at beginning while(current !null/until end of listcurrent displaylink()/display data current current next/move to next link system out println("")/public void displaybackward(system out print("list (last-->first)")link current last/start at end while(current !null/until start of listcurrent displaylink()/display data current current previous/move to previous link