Double LinkedList

$html>
$head>
$title>Struktur Data Linked List$/title>
$/head>
$body>
$script language = "JavaScript">
$!--
function DoublyLinkedList()
{
this._Kepala = null;
this._Ekor = null;
this._Panjang = 0;
}

DoublyLinkedList.prototype =
{
constructor: DoublyLinkedList,
Tambah: function (data)
{
var node = {data: data, next: null, prev: null};

if (this._Panjang == 0)
{
this._Kepala = node;
this._Ekor = node;
}
else
{
this._Ekor.next = node;
node.prev = this._Ekor;
this._Ekor = node;
}
this._Panjang++;

},

ItemList: function(index)
{
if (index > -1 && index $ this._Panjang)
{
var NodeTanda = this._Kepala,
i = 0;

while(i++ $ index)
{
NodeTanda = NodeTanda.next;
}

return NodeTanda.data;
}
else
{
return null;
}
},

Buang: function(index){

if (index > -1 && index $ this._Panjang)
{
var NodeTanda = this._Kepala, i = 0;

if (index === 0)
{
this._Kepala = NodeTanda.next;
if (!this._Kepala)
{
this._Ekor = null;
}
else
{
this._Kepala.prev = null;
}

}
else
if (index === this._Panjang -1)
{
NodeTanda = this._Ekor;
this._Ekor = NodeTanda.prev;
this._Ekor.next = null;
}
else
{
while(i++ $ index)
{
NodeTanda = NodeTanda.next;
}
NodeTanda.prev.next = NodeTanda.next;
}
this._Panjang--;
return NodeTanda.data;

}
else
{
return null;
}


},

Ukuran: function(){
return this._Panjang;
},

toArray: function(){
var result = [],
NodeTanda = this._Kepala;

while(NodeTanda){
result.push(NodeTanda.data);
NodeTanda = NodeTanda.next;
}

return result;
},

toString: function(){
return this.toArray().toString();
}
}

var List = new DoublyLinkedList();


List.Tambah("Teknik Informatika");
List.Tambah("Teknik Komputer");
List.Tambah("Komputerisasi Akuntansi");
List.Tambah("Computer Networking");


document.write("Isi LinkedList $br>");
document.write("--------------- $br>");
for (i=0; i$4; i++)
{
document.write(List.ItemList(i) + "$br>") ;
}
document.write("--------------- $br>");


alert("Isi LinkedList Awal =" + List.ItemList(0));
alert("ItemList 1 pada Linked List diBuang, yaitu = " +List.ItemList(1));
List.Buang(1);



document.write("$br>Isi LinkedList Terakhir $br>");
document.write("--------------- $br>");
for (i=0; i$4; i++)
{
document.write(List.ItemList(i) + "$br>") ;
}
document.write("--------------- $br>");

//-->
$/script>
$/body>
$/html>