HashTable and HashMap

[Abhishek Reddy]

can you tell me the difference between hashtable and hashmap and when to use them?

[Christophe Verré]

Hashtable is synchronized.
You will probably use HashMap most of the time.

[Jesper de Jong]

Also, Hashtable does not allow the keys or values to be null, while HashMap does.

Hashtable is one of the old legacy collection classes from Java 1.1. You should use HashMap as much as possible instead.

[Paul Sturrock]

Not really an advanced question. Moving...