contest/study/collections.MD

Common Java Data Structures Summary

Java contains many object based data structures that you can import, some used more than others (ArrayList, for example).

Not all of them work in familiar ways, and their methods can be confusing without proper usage, study, and a quick explanation over how they're used.

Interfaces

Collection

Common Implementing SubInterfaces:

• Deque
• List
• Queue
• Set
• SortedSet

Common Implementing Classes:

• ArrayList
• ArrayDeque
• EnumSet
• HashSet
• LinkedList
• PriorityQueue
• Stack
• TreeSet

Iterable

Common Implementing SubInterfaces

• Collection
• Deque
• List
• Queue
• Set
• SortedSet

Common Implementing Classes:

• ArrayDeque
• ArrayList
• EnumSet
• HashSet
• LinkedList
• PriorityQueue
• Stack
• TreeSet

List

Super Interfaces:

• Collection
• Iterable

Implementing Classes:

• ArrayList
• LinkedList
• Stack

A unordered collection (also known as a sequence) that allows precise control over where each element is inserted in a list.

Users have methods allowing all of the following to methods:

• 4 methods providing positional index-based access to list elements.
• 1 method for accessing a special iterator, ListIterator allowing element insertion and replacement starting from a specified position.
• 2 methods for searching for a specified object. Usually costly linear searches.
• 2 methods for efficiently inserting and removing multiple elements at an arbitrary point.

Set

Queue

Deque

SortedSet

Map

SortedMap

NavigableMap

Classes

ArrayList

LinkedList

Stack

PriorityQueue

TreeSet

ArrayDeque

EnumSet

HashSet

HashMap