Package com.hephec.Map;
Import Java.util.HashMap;
Import java.util.Hashtable;
Import Java.util.Iterator;
Import Java.util.Map;
Import Java.util.TreeMap;
Class Hahsmaps
{
public static void Main (string[] args)
{
Map<string,string> map=new hashmap<string,string> ();
Map.put ("A", "AAA");
Map.put ("B", "BBB");
Map.put ("C", "CCC");
Map.put ("D", "ddd");
Iterator<string> Iterator=map.keyset (). Iterator ();
while (Iterator.hasnext ()) {
Object Key=iterator.next ();
System.out.println ("Map.get (Key) is:" +map.get (key));
}
Define Hashtable, which is used to test
Hashtable<string,string> tab=new hashtable<string,string> ();
Tab.put ("A", "AAA");
Tab.put ("B", "BBB");
Tab.put ("C", "CCC");
Tab.put ("D", "ddd");
Iterator<string> Iterator_1=tab.keyset (). Iterator ();
while (Iterator_1.hasnext ()) {
Object Key=iterator_1.next ();
System.out.println ("Tab.get (Key) is:" +tab.get (key));
}
Treemap<string,string> tmp=new treemap<string,string> ();
Tmp.put ("A", "AAA");
Tmp.put ("B", "BBB");
Tmp.put ("C", "CCC");
Tmp.put ("D", "ddd");
Iterator<string> Iterator_2=tmp.keyset (). Iterator ();
while (Iterator_2.hasnext ()) {
Object Key=iterator_2.next ();
System.out.println ("Tmp.get (Key) is:" +tmp.get (key));
}
}
}
The difference between HashMap and TreeMap in Java is deeply understood