Special Edition Using Java 2 Standard Edition

Which Collection Class to Use?

Given the number of collection classes, the difficulty is sometimes in deciding which one to use for a particular need. The following guidelines outline some recommendations you should consider when making this choice:

• Use the general-purpose implementations in the collections framework instead of Vector, Stack, and Hashtable, unless you are restricted to a JDK 1.1.x version.

• Use ArrayList for ordered collections (instead of Vector).

• Use HashSet for unordered collections.

• Use HashMap for key-value associations (instead of Hashtable).

• Use ArrayList when random access of the elements is more important than the time required to perform inserts and removals in the middle of the list.

• Use LinkedList when the performance of ...