LinkedList.js

class LinkedList {

  constructor(...values) {
    this.head = null;
    this.tail = null;
    this.size = 0;
    if (values.length > 0) {
      values.forEach(this.add.bind(this));
    }
  }

  // Create new node
  createNode(value) {
    return {
      value,
      next: null
    };
  }

  // Find first node by value
  find(value) {

    let node = this.head;

    while (node) {

      if (value === node.value) {
        break;
      }

      node = node.next;

    }

    return node;

  }

  // Insert node at tail
  add(value) {

    const node = this.createNode(value)

    if (!this.head) {
      this.head = node;
      this.tail = node;
    } else {
      this.tail.next = node;
      this.tail = node;
    }

    this.size++;

  }

  // Remove node by value
  remove(value) {

    if (!this.head) {
      return;
    }

    if (this.head.value === value) {

      this.head = this.head.next
      this.size--;

    }

    let previous = this.head;
    let current = previous.next;

    while (current) {

      if (current.value === value) {
        break;
      }

      previous = current
      current = previous.next

    }

    if (!current) {
      return;
    }

    if (!current.next) {
      this.tail = current;
    }

    // Remove ref
    previous.next = current.next
    this.size--;

  }

}