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Singly Linked List Data Structures

Last Updated: 20 January, 2025 🕓 5 Mins Read

Hey, In this article we are going to learn all about Singly Linked List in detail and their structure, which allows for each node to point to the next node of the list. Further we will see its operations, complexity, implementation, advantages, disadvantages and more.

What is Singly Linked List?

A Singly Linked List is a linear (ordered) data structure that contains a collection of elements, and each element is connected to its next element in a sequence.

Each element in a singly linked list is called a Node. The node consists of two fields: a data field and the reference field (address of the next node).

There is a HEAD pointer, which points to the first node of the singly linked list, and if the list is empty, then it stores NULL and the last node is called the Tail, and it stores NULL in the reference field (next).

A singly linked list can traverse only in the forward direction because each node contains the address of the next node.

Operations on Singly Linked List

There are the following operations that can be performed on the singly linked list.

Insertion:

A new node can be added at the following positions of the singly linked list.
- Insert a node at the beginning
- Insert a node at the end
- Insert a node at the specific position
Deletion:

An existing node can be deleted at the following positions of the singly linked list.
- Delete a node at the beginning
- Delete a node at the end
- Delete a node at the specific position
Traversal:

Traversal can be performed in only farward direction. Start traversing from the head and move through each node using the next pointers till the last node of the singly linked list.
Searching:

We can search a specific node in the singly linked list.
- Search a specific node

Singly Linked List implementation in Java

  
  // Java program to implementation Singly Linked List
  class Node {
    public int data;
    public Node next;
    public Node(int data) {
      this.data = data;
      this.next = null;
    }
  }
  
  public class SinglyLinkedList {
    // Create a head node which will point to the first node of the list
    Node head;
    
    // Method to insert a node in the list
    public void insert(int data) {
      Node newNode = new Node(data);
      if (head == null) {
        head = newNode;
        return;
      }
      Node last = head;
      while (last.next != null) {
        last = last.next;
      }
      last.next = newNode;
    }
    
    // Method to print list
    public void printList() {
      Node node = head;
      while (node != null) {
        System.out.print(node.data + " ");
        node = node.next;
      }
    }
    
    public static void main(String[] args) {
      SinglyLinkedList list = new SinglyLinkedList();
      
      // Insert elements in the list
      list.insert(10);
      list.insert(20);
      list.insert(30);
      list.insert(40);
      list.insert(50);
      
      // Print list elements
      System.out.print("Singly Linked List elements: ");
      list.printList();
    }
  }

Output

  Singly Linked List elements: 10 20 30 40 50

In the above example, the Node class represents a single element of the linked list, and the SinglyLinkedList class is used to create a linked list, insert a node in the list, and display the elements of the linked list.

Advantages of Singly Linked List

Dynamic data structure
No memory wastage
Easy Implementation
Insertion and Deletion Operations
Flexible
Efficient for large data
Scalability

Disadvantages of Singly Linked List

A linked list is a very popular and flexible data structure, but it has some certain disadvantages as well. Some of the key disadvantages of linked lists are:

Random access is inefficient
Additional memory required for pointers
Potential for memory fragmentation
Potential for Memory Leaks

That's all, guys. I hope this article is helpful for you.

Happy Learning... 😀

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