singly-linked-list.js

class Node {
  constructor(element) {
    this.element = element;
    this.next = null;
  }
}

class LinkedList {
  constructor() {
    this.head = new Node('head');
  }
  
  find(item) {
    let currentNode = this.head;
    while (currentNode.element !== item) {
      currentNode = currentNode.next;
    }
    return currentNode;
  }
  
  findPrevious(item) {
    let currentNode = this.head;
    while (currentNode.next !== null && currentNode.next.element !== item) {
      currentNode = currentNode.next;
    }
    return currentNode;
  }
  
  display() {
    let currentNode = this.head;
    while (currentNode.next !== null) {
      console.log(currentNode.element);
      currentNode = currentNode.next;
    }
  }
  
  insert(element, item) {
    let newNode = new Node(element);
    let currentNode = this.find(item);
    newNode.next = currentNode.next;
    currentNode.next = newNode;
  }
  
  remove(item) {
    let previousNode = this.findPrevious(item);
    if (previousNode.next !== null) {
      previousNode.next = previousNode.next.next;
    }
  }
}