Java

Java

Java java.util

Java

Arrays

Arrays

int[] array = new int[5];

Lists

Java ArrayList LinkedList

List<String> arrayList = new ArrayList<>();
List<Integer> linkedList = new LinkedList<>();

ArrayList:

LinkedList:

Sets

Sets HashSet TreeSet

Set<String> hashSet = new HashSet<>();
Set<Integer> treeSet = new TreeSet<>();

HashSet:

• HashMap

TreeSet:

• TreeSet
• null

Maps

Maps HashMap TreeMap

Map<String, Integer> hashMap = new HashMap<>();
Map<String, Integer> treeMap = new TreeMap<>();

HashMap:

TreeMap:

Stack

StackLast In, First OutLIFO

Stack<Integer> stack = new Stack<>();

Stack :

• LIFO

Queue

QueueFIFO LinkedList PriorityQueue

Queue<String> queue = new LinkedList<>();

Queue :

• FIFO
• LinkedList, PriorityQueue, ArrayDeque

Heap

Heap

PriorityQueue<Integer> minHeap = new PriorityQueue<>();
PriorityQueue<Integer> maxHeap = new PriorityQueue<>(Collections.reverseOrder());

Trees

Java TreeNode

class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;
    TreeNode(int x) { val = x; }
}

Graphs

Java

Java

Java2 -(Collection)

Enumeration

Enumeration, The Enumeration

nextElement

Enumeration

BitSet

""

BitSet

Vector

VectorVector

Vector

Vector

(Vector)

Stack

StackLIFO

Stack

Dictionary

Dictionary

Dictionary

Dictionary

Dictionary

Dictionary Java deprecated Map HashMapTreeMap Dictionary

Map Java

Hashtable

Hashtable

HashTable

Properties

Properties Hashtable.Properties .

Properties JavaSystem.getProperties()

Properties