Map Traversal ( Collection)

How to Traverse Map in different ways

package com.mkyong;
 
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
 
public class LoopMap {
 
  public static void main(String[] args) {
 
 // initial a Map
 Map<String, String> map = new HashMap<String, String>();
 map.put("1", "Jan");
 map.put("2", "Feb");
 map.put("3", "Mar");
 map.put("4", "Apr");
 map.put("5", "May");
 map.put("6", "Jun");
 
 System.out.println("Example 1...");
 // Map -> Set -> Iterator -> Map.Entry -> troublesome
 Iterator iterator = map.entrySet().iterator();
 while (iterator.hasNext()) {
  Map.Entry mapEntry = (Map.Entry) iterator.next();
  System.out.println("The key is: " + mapEntry.getKey()
   + ",value is :" + mapEntry.getValue());
 }
 
 System.out.println("Example 2...");
 // more elegant way
 for (Map.Entry<String, String> entry : map.entrySet()) {
  System.out.println("Key : " + entry.getKey() + " Value : "
   + entry.getValue());
 }
 
 System.out.println("Example 3...");
 // weired way, but work anyway
 for (Object key : map.keySet()) {
  System.out.println("Key : " + key.toString() + " Value : "
   + map.get(key));
 }
 
  }
 
}