LinkedHashMap preserves the insertion order Hashtable is synchronized, in contrast to HashMap. This gives us the reason that HashMap should be used if it is thread-safe, since Hashtable has overhead for synchro
Hashtable is synchronized, in contrast to HashMap. This gives us the reason that HashMap should be used if it is thread-safe, since Hashtable has overhead for synchronization. 2. HashMap If key of the HashMap is self-defined objects, then equals() and hashCode() contract need to be f...