Collections

A collection is a data structure which contains a set of data. The data stored in the collection is encapsulated and the access to the data is only possible via predefined methods. Typical collections are lists, sets, maps, queues, stacks, and trees. Java provides an interface for each collection type and one or several implementations for this interface.

Table of contents

• Arrays
• Lists
• Sets
• Maps
• Bags
• Covariance and invariance
• The hashCode() and equals() methods
• Queue, Priority Queue and Stack
• Concurrent Collections
• Java Collections Framework
• Miscellaneous