Java FAQ: Top Questions
16. What are Java collections, and what is the Collections Framework?
The
Java Collections Framework
is a set of classes and interfaces in the
java.util
package for storing and manipulating groups of objects (collections).
-
Core Interfaces:
List(ordered, allows duplicates),Set(no duplicates),Map(key-value pairs). -
Implementations:
ArrayList,LinkedList(List);HashSet,TreeSet(Set);HashMap,TreeMap(Map). -
Utilities:
The
Collectionsclass provides methods likesort,reverse, andshuffle. -
Generics:
Collections use generics for type safety (e.g.,
List).