How does one convert a HashMap to a List in Java?

Question

In Java, how does one get the values of a HashMap returned as a List?

Answer 1

HashMap<Integer, String> map = new HashMap<Integer, String>(); map.put (1, "Mark"); map.put (2, "Tarryn"); List<String> list = new ArrayList<String>(map.values()); for (String s : list) {     System.out.println(s); } 

Answer 2

Assuming you have:

HashMap<Key, Value> map; // Assigned or populated somehow. 

For a list of values:

List<Value> values = new ArrayList<Value>(map.values()); 

For a list of keys:

List<Key> keys = new ArrayList<Key>(map.keySet()); 

Note that the order of the keys and values will be unreliable with a HashMap; use a LinkedHashMap if you need to preserve one-to-one correspondence of key and value positions in their respective lists.