java - how to return HashSet from a method? -

i struggling how recall data stored in hashmap , hashset , method return values stored in them , size data?

public hashset <room>  getoccupiedrooms(){     return occupiedrooms.size(); } 

and not compile not sure. , wound return data stored.

cheers

you need iterate on hashset, check every room if it's occupied , add room diffferent hashset.

public hashset<room>  getoccupiedrooms(){ hashset<room> tempset = new hashset<room>(); // iterate start // if room occupied, add room tempset // iterate end // return tempset