Using keys to search and retrieve values from HashMap

Question

I've been fiddling around with this problem for a while and can't seem to find any working solution. What I have is a method that I want to return all values from a HashMap, but instead of using the regular keys for a HashMap (0, 1, 2, 3), my keys are different numbers such as 51414, 62513, etc.
public Car[] getAllCars() {
          Map<Integer, Car> myCars = system.getCars(); //getCars() returns HashMap of Car objects from another class
          Car[] c = new Car[myCars.size()];
          if(myCars.size()!=0) // ensure map is populated
               for(int i=0; i<myCars.size(); i++)
                    myCars.get(i);
          return c;    
     }So what's happening at the moment is it loops through myCars and gets some values, but only those ones at the keys of 0-15 (the size of the Map). What I need is to get the Keys from myCars and use them to return all Car objects. The HashMap API has something called KeySet() which I think could help me, but I can't get that working.
Any ideas?

Answer 1

DiscoInferno wrote:
Short of an SSCCE I think this might more accurately describe what I'm after.
public Car[] getAllCars() {
          Map<Integer, Car> myCars = system.getCars();  //getCars() returns HashMap of Car objects from another class
          Car[] c = new Car[myCars.size()];
          Set<Integer> s = holds.keySet();
          Iterator keyIter = s.iterator();
          if(myCars.size()!=0)
               while (keyIter.hasNext()) {
                    Object key = keyIter.next();
                    Car cc = myCars.get(key);
                    System.out.println(myCars.get(key));
          return null;
     }What that does is gets the Car object that matches the specified key. What I need is for it to be returnable as an array of Car objects. I don't want it to print, but the output that is printed is basically what I want to be returned to an array.First, I'm not sure how you managed to find keySet() and not find values().
Second, okay, so you know how to get each value. Do you not know how to set a value in an array? Do you not know how to return a value from a method? Google can help you find tutorials for those. Otherwise, I have no idea what difficulty you're having.