treemap java code example

Example 1: TreeMap headMap() method in java

import java.util.SortedMap;
import java.util.TreeMap;
public class TreeMapHeadMapMethodExample
{
   public static void main(String[] args)
   {
      TreeMap<Integer, String> tm = new TreeMap<Integer, String>();
      // map string values to integer keys
      tm.put(65, "mango");
      tm.put(63, "apple");
      tm.put(35, "grapes");
      tm.put(60, "pineapple");
      tm.put(26, "banana");
      System.out.println("Given TreeMap is: " + tm);
      // create SortedMap for map head
      SortedMap<Integer, String> sm = new TreeMap<Integer, String>();
      sm = tm.headMap(60);
      // Getting map head
      System.out.println("headmap is: " + sm);
   }
}

Example 2: TreeMap in java

import java.util.Map;
import java.util.TreeMap;
public class TreeMapExample
{
   public static void main(String[] args) 
   {
      TreeMap<Integer, String> tm = new TreeMap<Integer, String>();    
      tm.put(1000, "Apple");    
      tm.put(1002, "Raspberry");    
      tm.put(1001, "Velvet apple");    
      tm.put(1003, "Banana");    
      for(Map.Entry obj : tm.entrySet())
      {    
         System.out.println(obj.getKey() + " " + obj.getValue());    
      }
   }
}

Example 3: java treemap

import java.util.*;

// Declare the variable using the interface of the object for flexibility.
// Non-primative data types only.
Map<Integer, String> mambo = new TreeMap<Integer, String>();

mambo.put(key, value);
// TreeMap will be sorted by key.
// Work with any comparable object as a key.

mambo.put(1, "Monica");
mambo.put(2, "Erica");
mambo.put(3, "Rita");

Example 4: treemap

- TreeMap doesn't have null key and keys are sorted
 Can contain only unique keys and keys are sorted in ascending order.

Example 5: treemap in java

TreeSet: Can contain only unique values and it is sorted in ascending order
TreeMap: Can contain only unique keys and keys are sorted in ascending order.