ArrayList vs LinkedList in Java

Last Updated : 29 May, 2026

ArrayList and LinkedList are two commonly used classes in Java that implement the List interface. Both maintain insertion order and allow duplicate elements, but they differ in memory structure, data access, and performance for insertion and deletion operations.

ArrayList is based on a dynamic array, while LinkedList uses a doubly linked list
ArrayList provides faster random access, whereas LinkedList is efficient for frequent insertions and deletions
Both are part of the Java Collections Framework and support generic data storage

ArrayList

ArrayList is a class in Java Collections Framework that stores elements in a sequential manner and automatically grows in size when needed. It is widely used for fast data retrieval and managing ordered collections of elements.

Allows storing elements of the same or different data types using generics
Supports index-based operations like searching, updating, and accessing elements
Maintains insertion order of elements during storage and retrieval

Syntax:

ArrayList<DataType> listName = new ArrayList<>();

Output

[Java, Python, C++]
Element at index 1: Python

Explanation:

Elements are stored in contiguous memory locations
Accessing elements using index is fast
When the internal array becomes full, a new larger array is created and elements are copied

LinkedList

LinkedList is a class in Java Collections Framework that stores elements as interconnected nodes instead of a continuous memory structure. It is mainly used when frequent insertion and deletion operations are required.

Implements both List and Deque interfaces in Java
Allows efficient insertion and deletion of elements from both ends
Maintains insertion order and supports duplicate elements

Syntax:

LinkedList<DataType> listName = new LinkedList<>();

Output

[Java, Python, C++]
First element: Java

Explanation:

Each element is stored as a node. Every node contains:
Data
Reference to previous node
Reference to next node
No shifting of elements during insertion or deletion

ArrayList vs LinkedList

Feature	ArrayList	LinkedList
Definition	A resizable array implementation of the List interface	A doubly-linked list implementation of the List interface
Data Storage	Stores elements in contiguous memory locations	Stores elements as nodes linked using pointers
Access Time	Fast random access using index (O(1))	Slower random access (O(n))
Insertion/Deletion	Slower in middle or beginning (O(n)), faster at end	Faster for insertion/deletion anywhere (O(1) if position known)
Memory Usage	Less memory overhead	More memory due to storing pointers
Iteration	Faster iteration using index-based loop	Faster iteration using iterator
Use Case	Best for frequent access and rare modifications	Best for frequent insertions and deletions