Java: Access element of an arrayList which is a value in a TreeMap

Question

I have a TreeMap which maps a key to an ArrayList. I would like access each of the elements stored inside each ArrayList of the TreeMap.

Is there a method to do this?

The elements of the ArrayList are of type String.

You have a Map which maps a key to a List — you should ignore the fact that a TreeMap and an ArrayList were chosen as the implementation details, and program to the interfaces. This doesn't change the question and shouldn't affect the answer. — Stephen P
– Stephen P, Commented Mar 21, 2017 at 19:37

Guillaume F. · Accepted Answer · 2017-03-21 17:25:51Z

1

I understand that you want to loop over all the elements in your TreeMap lists. You can achieve this easily with Java 8 streams:

treeMap.values().stream().flatMap(List::stream).forEach(element -> doStuff(element));

answered Mar 21, 2017 at 17:18

Guillaume F.

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