Java HashMap: How to get a key and value by index?

Question

I am trying to use a HashMap to map a unique string to a string ArrayList like this:

HashMap>

Basical

Answer 1

If you don't care about the actual key, a concise way to iterate over all the Map's values would be to use its values() method

Map> myMap;

for ( List stringList : myMap.values() ) {
    for ( String myString : stringList ) {
        // process the string here
    }
}

The values() method is part of the Map interface and returns a Collection view of the values in the map.