can i have in javascript as well? thanks

Of course, sometimes the community can help. Here's the JavaScript I built:

// Node for a Singly Linked List

class Node {
  /**
   * Object to store single node of a linked list
   * Contains data and link do next list
  */
  data;
  next_node;

  constructor( data ) {
        this.data = data;
    }
}

// Node for a Doubly Linked List

class LinkedNode {
  data;
  next_node;
  previous_node;

  constructor( data ) {
        this.data = data;
    }
}

/** Linked List
  * This works with both types of lists. Create a Node or LinkedNode as appropriate
*/

class LinkedList {
  head;

  is_empty() {
    return ( this.head === undefined );
  }

  size() {
    let current = this.head,
        count = 0;

    while ( current ) {
      count++;
      current = current.next_node;
    }

    return count;
  }
}

It was noted at the top of these links to contact you guys for the copy of this lesson in another language we’re looking for. In my situation...Javascript. I did that, but they said that email address was no longer in service. So, they advised to post it here in the community, which seems odd since someone previously asked the same question here and they directed them back to that email address??....Would really appreciate the JS version of the links below......Many thanks

Singly and Doubly:

https://teamtreehouse.com/library/introduction-to-data-structures/building-a-linked-list/singly-and-doubly-linked-lists-2

Or…

This one, which covers singly, doubly with adding node, inserting nodes, search nodes, and delete nodes

https://teamtreehouse.com/library/introduction-to-data-structures/building-a-linked-list/linked-lists-operations

You may have missed the note at the top of the page:

Note: If code is not provided below in the language you are looking for, send an email to content+cs@teamtreehouse.com

https://www.geeksforgeeks.org/implementation-linkedlist-javascript/ this was the best JavaScript implementation I've found so far. It's nice to take the code from there and bring it to JSFiddle/etc and play with it.