Real Double Linked list

by Nyle Anderson

HTML

<input type = "textbox" id="v" value="aaa" />
<input type="button" value="Add Node" onclick="addNode()" />

<div id="output">

</div>

JavaScript

//working sorted double linked list
function LinkedList() { //defines the list
	this.head = null;
  this.tail = null;
  this.length = 0;
}

function Node() { //defines the node
	this.next = null;
  this.prev = null;
  this.content = null;
}

LinkedList.prototype.add = function(_content) {
//defines adding node
	var node = new Node(); node.content = _content

	if(this.head == null){
  	this.head = node; this.length = 1;
    return node;
  }
  
  if (this.tail == null) {
  	this.tail = node;
    this.tail.prev = this.head;
    this.head.next = this.tail;
    this.length = 2;
    return node;
    }
    
    this.tail.next = node;
    node.prev = this.tail;
    this.tail = node;
    this.length++;
    return node;
    
  }
  
LinkedList.prototype.addSorted = function(_content) {
	if(this.head == null) {return this.add(_content); }
  var node = new Node(); node.content = _content;
  
  if(_content < this.head.content) {
  	this.head.prev = node;
    node.next = this.head;
    this.head = node;
  	return node;
  }
  
  var cnode = this.head;
  while (cnode.next != null) {
  	if ((_content > cnode.content) && (_content < cnode.next.content)){
      node.prev = cnode;
      cnode.prev = node;
      node.next = cnode.next;
      cnode.next.prev = node;
      cnode.next = node;
 
  }
  //while node.content > cnode.content || node.content > cnode.content.next
  //node
  cnode = cnode.next;
  return node; 
}
  return this.add(_content);
  }
//to make a stack add pop and push functions
//to make a queue add enqueue and dequeue functions
LinkedList.prototype.print = function () {
	if (this.head == null) return "Empty List";
  var s = "";
  var node = this.head; 
  while (node != null){
  	s += node.content + "<br/>   ";
    node = node.next;
  }
  return s;
}
var aList = new LinkedList();

function addNode() {
	var c = document.getElementById("v").value;
  aList.addSorted(c);
  document.getElementById("output").innerHTML=aList.print();
  document.getElementById("v").value =...