import java.util.*;
 
public class HashMapDemo
{
  public static void main(String[] args)
  {
    // Create a map and put some items into it
    Map<String, Integer> months = new HashMap<String, Integer>();
    months.put("September", 30);
    months.put("July", 31);
    months.put("January", 31);
    months.put("May",31);
    months.put("November", 30);
 
    // List all the items in the map
    for(String month : months.keySet())
    {
      System.out.println(month + " : " + months.get(month) );
    }       
    // Alternate technique 
    // for( Map.Entry item: months.entrySet())
    // {
    //   System.out.println(item.getKey() + " : " + item.getValue() );
    // }       
     
    System.out.println("Contains May? " + months.containsKey("May"));
    System.out.println("Contains ABC? " + months.containsKey("ABC"));
    System.out.println("Value of July? " + months.get("July"));
    months.put("May", 3);
    System.out.println("Value of May? " + months.get("May"));
 
  }
}
/*
January : 31
November : 30
May : 30
July : 31
September : 30
Contains May? true
Contains ABC? false
Value of July? 31
Value of May? 3
*/