keySet() usage for > maps

Question

I defined a hashmap as follows:

HashMap<String, List<String>> hashmap = new HashMap<String, List<String>>();

And I would like to retrieve the complete list of keys and print them. However, keySet() does not work for maps defined as <String, List<String>>

Set<String, List<String>> keys = hashmap.keySet();

How could I solve this problem?

it returns a `keySet`, so only `Set` without the `List` – SomeJavaGuy Feb 18 '16 at 12:34 — SomeJavaGuy, Feb 18 '16 at 12:34

score 3 · Accepted Answer · edited May 23 '17 at 12:23

3

What you need is not the .keySet(), but rather the .entrySet():

Set<Map.Entry<String, List<String>>> keys = hashmap.entrySet();

More info:

edited May 23 '17 at 12:23

Community

answered Feb 18 '16 at 12:35

Konstantin Yovkov

1 Answers1