Java Map: TreeMap Example

·         Tree based implementation of the SortedMap interface

·         The keys are ordered according to their natural order

·         Less efficient than HashMap for insertion and mapping

·         Its methods are not synchronized

 

Example

package mycollectiontest;

import java.util.Collection;
import java.util.Iterator;
import java.util.TreeMap;

public class CollectionExample {

   public static void main(String[] args) {
      TreeMap<String, String> treeMap = new TreeMap<String, String>();

      // add key value pairs
      treeMap.put("1", "Java");
      treeMap.put("2", ".Net");
      treeMap.put("3", "Oracle");
      treeMap.put("4", "PHP");
      treeMap.put("5", "MainFrame");
      treeMap.put("6", "C++");

      Collection<String> c = treeMap.values();

      // Iterating
      Iterator<String> itr = c.iterator();

      // iterate through TreeMap values iterator
      while (itr.hasNext())
         System.out.println("TreeMap element " + itr.next());
   }

}

Output

TreeMap element Java
TreeMap element .Net
TreeMap element Oracle
TreeMap element PHP
TreeMap element MainFrame
TreeMap element C++