Map
A Map
is a collection that maps keys to values. Maps that come with
Java implement the java.util.Map
interface.
interface Map<K, V> {
V get(Object key);
V put(K key, V value);
// and more
}
HashMap
is one implementation of Map
you are likely to see and use.
import java.util.Map;
import java.util.HashMap;
class Main {
void main() {
Map<String, Integer> ages = new HashMap<>();
ages.put("Andor", 26);
ages.put("Bix", 27);
ages.put("Luthen", 59);
IO.println(ages);
}
}
Just like ArrayList
and List
, all the useful capabilities of HashMap
are available
via the Map
interface.