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Find Length of a Linked List (Iterative and Recursive)

Last Updated : 23 Jul, 2025
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Given a Singly Linked List, the task is to find the Length of the Linked List.

Examples:

Input: LinkedList = 1->3->1->2->1
Output: 5
Explanation: The linked list has 5 nodes.

Input: LinkedList = 2->4->1->9->5->3->6
Output: 7
Explanation: The linked list has 7 nodes.

Input: LinkedList = 10->20->30->40->50->60
Output: 6
Explanation: The linked list has 6 nodes.

Iterative Approach to Find the Length of a Linked List

The idea is similar to traversal of Linked List with an additional variable to count the number of nodes in the Linked List.

Steps to find the length of the Linked List:

  • Initialize count as 0. 
  • Initialize a node pointer, curr = head.
  • Do following while curr is not NULL
    • curr = curr -> next
    • Increment count by 1.
  • Return count.
C++ 
// Iterative C++ program to find length
// or count of nodes in a linked list

#include <bits/stdc++.h>
using namespace std;

// Link list node
class Node {
public:
    int data;
    Node* next;

    // Constructor to initialize a new node with data
    Node(int new_data) {
        data = new_data;
        next = nullptr;
    }
};

// Counts number of nodes in linked list
int countNodes(Node* head) {
  	
    // Initialize count with 0
    int count = 0;

    // Initialize curr with head of Linked List
    Node* curr = head;

    // Traverse till we reach nullptr
    while (curr != nullptr) {
        
      	// Increment count by 1
        count++;
        
      	// Move pointer to next node
        curr = curr->next;
    }
  	
  	// Return the count of nodes
    return count;
}

// Driver code
int main() {
  	
    // Create a hard-coded linked list:
    // 1 -> 3 -> 1 -> 2 -> 1
    Node* head = new Node(1);
    head->next = new Node(3);
    head->next->next = new Node(1);
    head->next->next->next = new Node(2);
    head->next->next->next->next = new Node(1);

    // Function call to count the number of nodes
    cout << "Count of nodes is " << countNodes(head);
    return 0;
}
C 
// Iterative C program to find length or count of nodes in a
// linked list

#include <stdio.h>
#include <stdlib.h>

// Link list node
struct Node {
    int data;
    struct Node* next;
};

// Function to create a new node
struct Node* createNode(int new_data) {
    struct Node* new_node = 
       (struct Node*)malloc(sizeof(struct Node));
    new_node->data = new_data;
    new_node->next = NULL;
    return new_node;
}

// Counts number of nodes in linked list
int countNodes(struct Node* head) {
    // Initialize count with 0
    int count = 0;

    // Initialize curr with head of Linked List
    struct Node* curr = head;

    // Traverse till we reach NULL
    while (curr != NULL) {
      
        // Increment count by 1
        count++;
        
      	// Move pointer to next node
        curr = curr->next;
    }
    
    // Return the count of nodes
    return count;
}

// Driver code
int main() {
  
    // Create a hard-coded linked list:
    // 1 -> 3 -> 1 -> 2 -> 1
    struct Node* head = createNode(1);
    head->next = createNode(3);
    head->next->next = createNode(1);
    head->next->next->next = createNode(2);
    head->next->next->next->next = createNode(1);

    // Function call
    printf("Count of nodes is %d", countNodes(head));
    return 0;
}
Java 
// Iterative Java program to count the number of
// nodes in a linked list

// Node class to define a linked list node
class Node {
    int data;
    Node next;

    // Constructor to initialize a new node with data
    Node(int newData) {
        data = newData;
        next = null;
    }
}

// Class to define methods related to the linked list
public class GFG {

    // Counts number of nodes in linked list
    public static int countNodes(Node head) {

        // Initialize count with 0
        int count = 0;

        // Initialize curr with head of Linked List
        Node curr = head;

        // Traverse till we reach null
        while (curr != null) {

            // Increment count by 1
            count++;

            // Move pointer to next node
            curr = curr.next;
        }
        // Return the count of nodes
        return count;
    }

    // Driver code
    public static void main(String[] args) {

        // Create a hard-coded linked list:
        // 1 -> 3 -> 1 -> 2 -> 1
        Node head = new Node(1);
        head.next = new Node(3);
        head.next.next = new Node(1);
        head.next.next.next = new Node(2);
        head.next.next.next.next = new Node(1);

        // Function call to count the number of nodes
        System.out.println("Count of nodes is "
                           + countNodes(head));
    }
}
Python 
# Iterative Python program to count the number of nodes
# in a linked list


class Node:
    def __init__(self, new_data):

        # Constructor to initialize a new node with data
        self.data = new_data
        self.next = None


def count_nodes(head):

    # Counts number of nodes in linked list
    # Initialize count with 0
    count = 0

    # Initialize curr with head of Linked List
    curr = head

    # Traverse till we reach None
    while curr is not None:
        # Increment count by 1
        count += 1

        # Move pointer to next node
        curr = curr.next

    # Return the count of nodes
    return count


# Driver code
if __name__ == "__main__":

    # Create a hard-coded linked list:
    # 1 -> 3 -> 1 -> 2 -> 1
    head = Node(1)
    head.next = Node(3)
    head.next.next = Node(1)
    head.next.next.next = Node(2)
    head.next.next.next.next = Node(1)

    # Function call to count the number of nodes
    print("Count of nodes is", count_nodes(head))
C# 
// Iterative C# program to find length or count of nodes
// in a linked list

using System;

// Link list node
class Node {
    public int Data;
    public Node Next;

    // Constructor to initialize a new node with data
    public Node(int newData) {
        Data = newData;
        Next = null;
    }
}

class GFG {
  
    // Counts number of nodes in linked list
    static int CountNodes(Node head) {
        
      	// Initialize count with 0
        int count = 0;

        // Initialize curr with head of Linked List
        Node curr = head;

        // Traverse till we reach null
        while (curr != null) {
            // Increment count by 1
            count++;

            // Move pointer to next node
            curr = curr.Next;
        }

        // Return the count of nodes
        return count;
    }

    static void Main() {

        // Create a hard-coded linked list:
        // 1 -> 3 -> 1 -> 2 -> 1
        Node head = new Node(1);
        head.Next = new Node(3);
        head.Next.Next = new Node(1);
        head.Next.Next.Next = new Node(2);
        head.Next.Next.Next.Next = new Node(1);

        // Function call to count the number of nodes
        Console.WriteLine("Count of nodes is "
                          + CountNodes(head));
    }
}
JavaScript 
// Iterative JavaScript program to find length
// or count of nodes in a linked list

// Linked List Node
class Node {

    // Constructor to initialize a new node
    // with data
    constructor(newData) {
        this.data = newData;
        this.next = null;
    }
}

// Counts number of nodes in linked list
function countNodes(head) {
    // Initialize count with 0
    let count = 0;

    // Initialize curr with head of Linked List
    let curr = head;

    // Traverse till we reach null
    while (curr !== null) {

        // Increment count by 1
        count++;

        // Move pointer to next node
        curr = curr.next;
    }

    // Return the count of nodes
    return count;
}

// Driver code

// Create a hard-coded linked list:
// 1 -> 3 -> 1 -> 2 -> 1
let head = new Node(1);
head.next = new Node(3);
head.next.next = new Node(1);
head.next.next.next = new Node(2);
head.next.next.next.next = new Node(1);

// Function call to count the number of nodes
console.log("Count of nodes is " + countNodes(head));

Output
Count of nodes is 5

Time complexity: O(n), Where n is the size of the linked list
Auxiliary Space: O(1), As constant extra space is used.

Recursive Approach to Find the Length of a Linked List:

The idea is to use recursion by maintaining a function, say countNodes(node) which takes a node as an argument and calls itself with the next node until we reach the end of the Linked List. Each of the recursive call returns 1 + count of remaining nodes.

C++ 
// Recursive C++ program to find length
// or count of nodes in a linked list

#include <bits/stdc++.h>
using namespace std;

// Link list node
class Node {
public:
    int data;
    Node* next;

    // Constructor to initialize a new node with data
    Node(int new_data) {
        data = new_data;
        next = nullptr;
    }
};

// Recursively count number of nodes in linked list
int countNodes(Node* head) {

    // Base Case
    if (head == NULL) {
        return 0;
    }

    // Count this node plus the rest of the list
    return 1 + countNodes(head->next);
}

// Driver code
int main() {
  
    // Create a hard-coded linked list:
    // 1 -> 3 -> 1 -> 2 -> 1
    Node* head = new Node(1);
    head->next = new Node(3);
    head->next->next = new Node(1);
    head->next->next->next = new Node(2);
    head->next->next->next->next = new Node(1);

    // Function call to count the number of nodes
    cout << "Count of nodes is " << countNodes(head);
    return 0;
}
C 
// Recursive C program to find length
// or count of nodes in a linked list

#include <stdio.h>
#include <stdlib.h>

// Link list node
struct Node {
    int data;
    struct Node* next;
};

// Constructor to initialize a new node with data
struct Node* createNode(int new_data) {
    struct Node* new_node = (struct Node*)malloc(sizeof(struct Node));
    new_node->data = new_data;
    new_node->next = NULL;
    return new_node;
}

// Recursively count number of nodes in linked list
int countNodes(struct Node* head) {
  	
    // Base Case
    if (head == NULL) {
        return 0;
    }

    // Count this node plus the rest of the list
    return 1 + countNodes(head->next);
}

// Driver code
int main() {
  	
    // Create a hard-coded linked list:
    // 1 -> 3 -> 1 -> 2 -> 1
    struct Node* head = createNode(1);
    head->next = createNode(3);
    head->next->next = createNode(1);
    head->next->next->next = createNode(2);
    head->next->next->next->next = createNode(1);

    // Function call to count the number of nodes
    printf("Count of nodes is %d\n", countNodes(head));
    return 0;
}
Java 
// Recursive Java program to find length
// or count of nodes in a linked list

// Link list node
class Node {
    int data;
    Node next;

    // Constructor to initialize a new node with data
    Node(int new_data) {
        data = new_data;
        next = null;
    }
}

// Recursively count number of nodes in linked list
public class GFG {
    public static int countNodes(Node head) {
      	
        // Base Case
        if (head == null) {
            return 0;
        }

        // Count this node plus the rest of the list
        return 1 + countNodes(head.next);
    }

    public static void main(String[] args) {
      	
        // Create a hard-coded linked list:
        // 1 -> 3 -> 1 -> 2 -> 1
        Node head = new Node(1);
        head.next = new Node(3);
        head.next.next = new Node(1);
        head.next.next.next = new Node(2);
        head.next.next.next.next = new Node(1);

        // Function call to count the number of nodes
        System.out.println("Count of nodes is "
                           + countNodes(head));
    }
}
Python 
# Recursive Python program to find length
# or count of nodes in a linked list

# Linked List Node
class Node:
    def __init__(self, new_data):
        self.data = new_data
        self.next = None

# Recursively count number of nodes in linked list
def count_nodes(head):
    # Base Case
    if head is None:
        return 0

    # Count this node plus the rest of the list
    return 1 + count_nodes(head.next)


# Driver code
if __name__ == "__main__":
  	
    # Create a hard-coded linked list:
    # 1 -> 3 -> 1 -> 2 -> 1
    head = Node(1)
    head.next = Node(3)
    head.next.next = Node(1)
    head.next.next.next = Node(2)
    head.next.next.next.next = Node(1)

    # Function call to count the number of nodes
    print("Count of nodes is", count_nodes(head))
C# 
// Recursive C# program to find length
// or count of nodes in a linked list

using System;

// Link list node
public class Node {
    public int Data;
    public Node Next;

    // Constructor to initialize a new node with data
    public Node(int new_data) {
        Data = new_data;
        Next = null;
    }
}

// Recursively count number of nodes in linked list
public class GFG {
    public static int CountNodes(Node head) {
      
        // Base Case
        if (head == null) {
            return 0;
        }

        // Count this node plus the rest of the list
        return 1 + CountNodes(head.Next);
    }

    // Driver code
    public static void Main() {
      
        // Create a hard-coded linked list:
        // 1 -> 3 -> 1 -> 2 -> 1
        Node head = new Node(1);
        head.Next = new Node(3);
        head.Next.Next = new Node(1);
        head.Next.Next.Next = new Node(2);
        head.Next.Next.Next.Next = new Node(1);

        // Function call to count the number of nodes
        Console.WriteLine("Count of nodes is " + CountNodes(head));
    }
}
JavaScript 
// Recursive Javascript program to find length
// or count of nodes in a linked list

// Link list node
class Node {
    constructor(data) {
        this.data = data;
        this.next = null;
    }
}

// Recursively count number of nodes in linked list
function countNodes(head) {

    // Base Case
    if (head === null) {
        return 0;
    }

    // Count this node plus the rest of the list
    return 1 + countNodes(head.next);
}

// Driver code
// Create a hard-coded linked list:
// 1 -> 3 -> 1 -> 2 -> 1
let head = new Node(1);
head.next = new Node(3);
head.next.next = new Node(1);
head.next.next.next = new Node(2);
head.next.next.next.next = new Node(1);

// Function call to count the number of nodes
console.log("Count of nodes is " + countNodes(head));

Output
Count of nodes is 5

Time Complexity: O(n), where n is the length of Linked List.
Auxiliary Space: O(n), Extra space is used in the recursion call stack.



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