Deep dive into Collection Framework in Java

🔹 What is the Java Collection Framework?

The Java Collection Framework is a set of classes and interfaces in java.util package used to store, retrieve, and manipulate data in the form of objects.

Think of it as a toolbox that provides various ways to handle groups of data (like lists, sets, maps) efficiently.

🔹 Main Interfaces in the Collection Framework

Interface	Purpose	Common Implementations
Collection	Root interface of all collections	List, Set, Queue
List	Ordered collection, allows duplicates	`ArrayList`, `LinkedList`, `Vector`
Set	No duplicates, unordered or ordered	`HashSet`, `LinkedHashSet`, `TreeSet`
Queue	FIFO (First-In-First-Out) structure	`LinkedList`, `PriorityQueue`
Map (not part of Collection interface)	Key-value pairs	`HashMap`, `TreeMap`, `LinkedHashMap`

🔹 Important Classes (Grouped)

✅ List Implementations

Class	Features
`ArrayList`	Resizable array, fast read, slow insert/delete
`LinkedList`	Doubly linked list, fast insert/delete
`Vector`	Like ArrayList but thread-safe

✅ Set Implementations

Class	Features
`HashSet`	No duplicates, no order
`LinkedHashSet`	Maintains insertion order
`TreeSet`	Sorted set (natural order or custom comparator)

✅ Queue Implementations

Class	Features
`PriorityQueue`	Elements sorted by priority
`LinkedList`	Can be used as a queue or deque

✅ Map Implementations

Class	Features
`HashMap`	Fast access, no order
`LinkedHashMap`	Maintains insertion order
`TreeMap`	Sorted keys

🔹 Basic Example

import java.util.*;

public class CollectionExample {
    public static void main(String[] args) {
        List<String> names = new ArrayList<>();
        names.add("Arko");
        names.add("Priyanka");

        for (String name : names) {
            System.out.println(name);
        }
    }
}

🔹 When to Use What?

Use List when you want ordered data with duplicates.
Use Set when you want unique data.
Use Map when you want to store key-value pairs.
Use Queue when you want to process elements in a specific order.

If you’d like, I can also provide a visual diagram, example code for each type, or a cheat sheet. Would you like to go deeper into any specific part like List, Set, Map, or algorithms used internally (like Hashing or Trees)?