TreeMap Operations and Iterate through TreeMap and TreeMap content in Java Pro

Basic TreeMap Operations

package com.java2novice.treemap;

          import java.util.TreeMap;

          public class MyBasicOperations

         {

          public static void main(String a[])

         {

               TreeMap hm = new TreeMap();

               hm.put("first", "First inserted");

               hm.put("second", "Second inserted");

               hm.put("third","Third inserted");

               System.out.println(hm);

                        System.out.println("Value of second: "+hm.get("second"));

               System.out.println("Is TreeMap empty? "+hm.isEmpty());

               hm.remove("third");

               System.out.println(hm);

               System.out.println("Size of the TreeMap: "+hm.size());

   }

}

How to iterate through TreeMap

package com.java2novice.treemap;

import java.util.Set;

import java.util.TreeMap;

public class MyTreeMapRead 

{

 public static void main(String a[])

{

               TreeMap hm = new TreeMap();

               hm.put("first", "First inserted");

               hm.put("second", "Second inserted");

               hm.put("third","Third inserted");

               System.out.println(hm);

               Set keys = hm.keySet();

               for(String key: keys)

                {

               System.out.println("Value of "+key+" is: "+hm.get(key));

               }

      }

}

How to copy Map content to another TreeMap

package com.java2novice.treemap;

import java.util.TreeMap;

public class MyTreeMapCopy 

{

public static void main(String a[])

{

               TreeMap hm = new TreeMap();

               hm.put("first", "First inserted");

               hm.put("second", "Second inserted");

               hm.put("third","Third inserted");

               System.out.println(hm);

   TreeMap subMap = new TreeMap();

               subMap.put("s1", "S1 Value");

               subMap.put("s2", "S2 Value");

               hm.putAll(subMap);

               System.out.println(hm);

   }

}