SortedMap is an interface which is available in java.util package which provides provides sorting of keys stored in a map.
SortedMap is an interface, we cannot create objects from it. In order to use the functionalities of the SortedMap interface, we need to use the class TreeMap that implements it.
How to use SortedMap:
SortedMap<Key, Value> numbers = new TreeMap<>();
| Method Name | Description |
|---|---|
| comparator() | returns a comparator that can be used to order keys in a map. |
| firstKey() | returns the first key of the sorted map. |
| lastKey() | returns the last key of the sorted map. |
| headMap(key) | returns all the entries of a map whose keys are less than the specified key. |
| tailMap(key) | returns all the entries of a map whose keys are greater than or equal to the specified key. |
| subMap(key1, key2) | returns all the entries of a map whose keys lies in between key1 and key2 including key1. |
import java.util.SortedMap;
import java.util.TreeMap;
class Main {
public static void main(String[] args) {
// Creating SortedMap using TreeMap
SortedMap<String, Integer> numbers = new TreeMap<>();
// Insert elements to map
numbers.put("Two", 2);
numbers.put("One", 1);
System.out.println("SortedMap: " + numbers);
// Access the first key of the map
System.out.println("First Key: " + numbers.firstKey());
// Access the last key of the map
System.out.println("Last Key: " + numbers.lastKey());
// Remove elements from the map
int value = numbers.remove("One");
System.out.println("Removed Value: " + value);
}
}