E4X is similar to XPath that is used to manipulate the structural xml in a scripting language. Here are some examples:

Delete node from XML

<root>
<level>
<detail></detail>
</level>
<level>
<detail></detail>
</level>
</root>

I want to make a copy of this XML (could be either of the three types of XML objects) and remove the <detail> nodes from every node no matter that hiarchy they are in.

private function testXML():void {
var xml:XML =
<root><level><detail></detail></level><level><detail></detail></level></root>
var test:XML = xml.copy();
delete test..*.detail;
trace(test.toXMLString());
}

Add new node to XML

var newItem:XML =
<level id=’1′>
<detail></detail>
</level>
test.appendChild(newItem);

Traverse

var myXML:XML =
<order>
<item id=’1′>
<menuName>burger</menuName>
<price>3.95</price>
</item>
<item id=’2′>
<menuName>fries</menuName>
<price>1.45</price>
</item>
</order>

myXML.item[0].menuName (for element traverse, use index to identify an element)
myXML.item.(@id=2).menuName (search an element using its attribute @)
myXML.item.(menuName==”xxx”).price

var total:Number = 0;
for each (var property:XML in myXML.item) {
var q:int = Number(property.@quantity);
var p:Number = Number(property.price);
var itemTotal:Number = q * p;
total += itemTotal;
trace (q + ” ” + property.menuName + ” $” + itemTotal.toFixed(2))
}
trace (”Total: $”, total.toFixed(2));

Assignment

myXML.item[0].menuName=”regular burger”;
myXML.item[1].menuName=”small fries”;
myXML.item[2].menuName=”medium cola”;

myXML.item.(menuName==”regular burger”).@quantity = “2″;
myXML.item.(menuName==”small fries”).@quantity = “2″;
myXML.item.(menuName==”medium cola”).@quantity = “2″;

var myXML:XML =
<order>
<book ISBN=”0942407296″>
<title>Baking Extravagant Pastries with Kumquats</title>
<author>
<lastName>Contino</lastName>
<firstName>Chuck</firstName>
</author>
<pageCount>238</pageCount>
</book>
<book ISBN=”0865436401″>
<title>Emu Care and Breeding</title>
<editor>
<lastName>Case</lastName>
<firstName>Justin</firstName>
</editor>
<pageCount>115</pageCount>
</book>
</order>

myXML.book –> XMLList (direct children of myXML object that has element name “book”)
myXML..lastName –> XMLList (any descendant that has element name “lastName”)
myXML.book.author.lastName –> XMLList
myXML.book[0]
myXML.book[0].title
myXML.child(”book”).title
myXML.book.(@ISBN=’0942407296′)
myXML.book[0].@ISBN –> output 0942407296
myXML.book.(title==’Emu Care and Breeding’)
myXML.book.(pageCount > 100)
myXML.book.(title.toString().search(’Emu’) > -1)

var myXML:XML =
<order>
<item id=’1′ quantity=’2′>
<menuName>burger</menuName>
<price>3.95</price>
</item>
<item id=’2′ quantity=’2′>
<menuName>fries</menuName>
<price>1.45</price>
</item>
</order>;

var total2:Number = 0;
for each (var prop:XML in myXML.item) {
total2 += prop.@quantity * prop.price;
}

http://www.devx.com/Java/Article/21383/1763/page/1