#java #collections #programming #datastructures

Java Concepts I’m Mastering – Part 12: ArrayList vs LinkedList

Continuing my journey of mastering Java fundamentals.

Today’s concept: ArrayList vs LinkedList — two important classes from the Java Collections Framework.

Both store collections of elements, but they work differently internally.

ArrayList

ArrayList is backed by a dynamic array.

import java.util.ArrayList;

ArrayList<String> list = new ArrayList<>();
list.add("Java");
list.add("Python");

Best for:

Fast random access

Reading data frequently

Limitation:

Inserting or deleting elements in the middle can be slower.

LinkedList

LinkedList is implemented using nodes connected by pointers.

import java.util.LinkedList;

LinkedList<String> list = new LinkedList<>();
list.add("Java");
list.add("Python");

Best for:

Frequent insertions and deletions

Working with queues or stacks

Limitation:

Accessing elements by index is slower.

Key Difference
ArrayList LinkedList
Dynamic array Doubly linked list
Faster access Slower access
Slower insert/delete Faster insert/delete

What I Learned

Use ArrayList for fast data access.

Use LinkedList when modifying data frequently.

Understanding data structures helps write efficient programs.

Next in the series: HashMap in Java (Key-Value Data Storage)