Linked List in JavaScript

A simple implementation of LinkedList along with traversal can be done like this in JavaScript:

(function(){
 'use strict';
 var LinkedList = function(){
  this.head = null;
 }
 
 LinkedList.prototype.appendToTail = function(data){
  var node = {
   "data":data,
   "next":null
  };
  
  if(this.head == null){
   this.head = node;
  }else{
   var current = this.head;
   while( current.next != null){
    current = current.next;
   }
   current.next = node;
  }
 }
  
  LinkedList.prototype.traverseList = function(){
      var current = this.head;
      while(current != null){
          console.log(current.data);
          current = current.next;
      }
  
  }
 
  var linkedList = new LinkedList();
  linkedList.appendToTail(20);
  linkedList.appendToTail(30);
  linkedList.appendToTail(40);
     
  linkedList.traverseList();
 
})()