CS5010-notes

week 1

lecture

• getters and setters:

1. public class Hashtable extends Dictionary<> implements Map<>
   
   public class HashMap  extends AbstractMap<> implements Map<>

2. multi-threaded concurrent environment

3. hashtable synchronized, no , so threaded safe

4. hashset not synchronized, multi-threaded change data together

5. in HashMap，null can be key

6. HashTable use hashCode directly