How to return a list of keys from a Hash Map?

List<String> yourList = new ArrayList<>(map.keySet());

This is will do just fine.

Using map.keySet(), you can get a set of keys. Then convert this set into List by:

List<String> l = new ArrayList<String>(map.keySet());

And then use l.get(int) method to access keys.

PS:- source- Most concise way to convert a Set<String> to a List<String>

map.keySet()

will return you all the keys. If you want the keys to be sorted, you might consider a TreeMap

Use the keySet() method to return a set with all the keys of a Map.

If you want to keep your Map ordered you can use a TreeMap.

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