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Find the length of the linked list in Java

In this tutorial, we will count the number of nodes in a given linked list.

Example – Program to find the length of the linked using Iterative way

class Node {
  int data;
  Node next;

  Node(int d) {
    data = d;
    next = null;
  }
}

public class LinkedList {
  Node head; 

  public void addData(int new_data) {
    
    Node new_node = new Node(new_data);
    new_node.next = head;
    head = new_node;
  }

  public int getCountNodes() {
    Node node = head;
    int count = 0;
    while (node != null) {
      count++;
      node = node.next;
    }
    return count;
  }
  

  public static void main(String[] args) {
    LinkedList list = new LinkedList();
    list.addData(1);
    list.addData(2);
    list.addData(3);
    list.addData(4);
    list.addData(5);

    System.out.println("Count of LinkedList is " + list.getCountNodes());
  }
}

Output

Count of LinkedList is 5

Example – Using Recursive way

class Node {
  int data;

  Node next;

  Node(int d) {
    data = d;
    next = null;
  }
}

public class LinkedList {
  Node head;

  public void addData(int new_data) {

    Node new_node = new Node(new_data);
    new_node.next = head;
    head = new_node;
  }

  public int getCountNodesUsingRecursive(Node node) {
    if (node == null)
      return 0;

    return 1 + getCountNodesUsingRecursive(node.next);
  }

  public static void main(String[] args) {
    LinkedList list = new LinkedList();
    list.addData(1);
    list.addData(2);
    list.addData(3);
    list.addData(4);
    list.addData(5);

    System.out.println("Count of LinkedList is " + list.getCountNodesUsingRecursive(list.head));
  }
}

Output

Count of LinkedList is 5
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