Java Collection Tutorial - Java TreeMap.headMap(K toKey)


TreeMap.headMap(K toKey) has the following syntax.

public SortedMap < K , V > headMap(K toKey) 


In the following code shows how to use TreeMap.headMap(K toKey) method.

import java.util.SortedMap;
import java.util.TreeMap;
// w  ww .j  av a  2 s  .  com
public class Main {
   public static void main(String[] args) {
      TreeMap<Integer, String>  treemap = new TreeMap<Integer, String> ();
      SortedMap<Integer, String>  treemaphead = new TreeMap<Integer, String> ();
      // populating tree map
      treemap.put(2, "two");
      treemap.put(1, "one");
      treemap.put(3, "three");
      treemap.put(6, "six");
      treemap.put(5, "from");
      // getting head map
      System.out.println("Checking values of the sorted map");
      System.out.println("Value is: "+ treemaphead);

The code above generates the following result.