Using keySet() method then changing the Set to a String Array? Java

java set treemap arrays
FudgeNouget picture FudgeNouget · Dec 31, 2012 · Viewed 24.5k times · Source

So this should be really simple since I know it's possible (I just don't understand 'Set' very much).

So basically there is this TreeMap, let's call it aTree. So I need to do something like:

somethingHereProbably = aTree.keySet();
somethingHereProbably.toStringArray();

Answer

Peter Lawrey picture Peter Lawrey · Dec 31, 2012

You can do

Map<String, Object> map = ...
String[] strings = map.keySet().toArray(new String[map.size()]);

This works for any kind of map, including TreeMap

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