Collections in Java

Collections in Java

A collection is an object that groups multiple elements into a single unit. Collections are used to store, retrieve, manipulate, and communicate aggregate data.

A collections framework is a unified architecture for representing and manipulating collections. All collections frameworks contain the following:

• Interfaces: Interfaces allow collections to be manipulated independently of the details of their representation.
• Implementations: These are the concrete implementations of the collection interfaces. They represent reusable data structures.
• Algorithms: Are the methods that perform useful operations, for example searching and sorting, on objects that implement collection interfaces. The algorithms are polymorphic: that is, the same method can be used on many different implementations the collection interface.

Benefits of the Java Collections Framework

• Reduces programming effort
• Increases program speed and quality
• Interoperability among unrelated APIs.
• Reduces effort to learn and to use new APIs
• Reduces effort to design new APIs
• Increases software reuse