Flex arraycollection getitemindex always return -1 - actionscript-3

Question

I'm facing the same problem. Can some explain me with a example?
My code is:
var dataList:ArrayCollection = new ArrayCollection([{name:"alauddn"}, {name:"ansari"}]);
private function getItemInd(event:MouseEvent):void{
var item:Object = new Object();
item.name = "ansari";
var ias:int = dataList.getItemIndex(item);
Alert.show(ias.toString() + ": " + item.name);
}
But it returns "-1:

Answer 1

getItemIndex is not comparing the value within your arrayCollection. The problem is that the getItemIndex() method matches exact object references, not objects with matching properties.
You should use a solution like this instead :
<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" creationComplete="creationCompleteHandler(event)">
<fx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.controls.Alert;
import mx.events.FlexEvent;
public var dataList:ArrayCollection = new ArrayCollection([{name:"alauddn"}, {name:"ansari"}]);
public function getItemIndexByProperty(array:ArrayCollection, property:String, value:String):Number
{
for (var i:Number = 0; i < array.length; i++)
{
var obj:Object = Object(array[i])
if (obj[property] == value)
return i;
}
return -1;
dataList.getItemIndex();
}
protected function creationCompleteHandler(event:FlexEvent):void
{
var ias:int = getItemIndexByProperty(dataList, "name", "ansari");
Alert.show(ias.toString() + " : " + dataList.getItemAt(ias).name);
}
]]>
</fx:Script>
</s:WindowedApplication>

Answer 2

getItemIndex only searches the root object. So for example this would work:
var dataList:ArrayCollection = new ArrayCollection(["alauddn", "ansari"]);
private function getItemInd(event:MouseEvent):void{
var name:String = "ansari";
var ias:int = dataList.getItemIndex(name);
Alert.show(ias.toString() + ": " + name);
}

Answer 3

You can use this.
private function getItemInd(event:MouseEvent):void{
for each( var item:Object in dataList){
if(item.name == "ansari")
{
var ias:int = dataList.getItemIndex(item);
Alert.show(ias.toString() + ": " + item.name);
break;
}
}
}