Difference between Hashmap and Hashtable:

Hashmap	Hashtable
Not Synchronized	Synchronized
Allows one null key and any number of null values	Not allow null keys or values
Iterator in Hashmap is fail fast	Enumeration in Hashtable is not fail fast
Not ThreadSafe	ThreadSafe
Faster then Hashtable	Slower then Hashmap
Extends AbstractMap class	Extends Dictionary class
Example code: import java.util.*; public class HashMapEg { public static void main(String args[]) { // creating hash map HashMap myhashmap = new HashMap(); // putting into hash map myhashmap.put(1, "my"); myhashmap.put(2, "name"); myhashmap.put(3, "is"); myhashmap.put(3, "Bhagat"); // getting values String val1=(String) myhashmap.get(1); String val2=(String) myhashmap.get(2); // … } }	Example code: import java.util.*; public class HashTableEg { public static void main(String args[]) { // creating hash table HashTable myhashtable = new HashTable(); // putting into hash table myhashtable.put(1, "my"); myhashtable.put(2, "name"); myhashtable.put(3, "is"); myhashtable.put(3, "Subhash"); // getting values String val1=(String) myhashtable.get(1); String val2=(String) myhashtable.get(2); // … } }