Subset of an arrayCollection

Question

How do I select a subset of an array
Collection to appear in a datagrid? For example, in the code below, how do I select only the records where pop > 2000?
<?xml version="1.0"?>
<!-- dpcontrols\SimpleDP.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"  creationComplete="creationCompleteHandler()">
    <mx:Script>
        <![CDATA[
import mx.collections.ArrayCollection;
[Bindable] private var _populations:ArrayCollection;
            public function creationCompleteHandler():void {
                _populations=new ArrayCollection;
                _populations.addItem({country: "Canada", continent:"NA", pop:"50"});
                _populations.addItem({country: "Ven", continent:"SA", pop:"1000"});
                _populations.addItem({country: "USA", continent:"NA", pop:"5000"});
                _populations.addItem({country: "Brazil", continent:"SA", pop:"4000"});
         ]]>
    </mx:Script>
    <mx:DataGrid  id="datagrid"   dataProvider="{_populations}" width="100%" height="100%" />
</mx:Application>

Answer 1

hi,
You use a filter function on your array collection, this is reasonably simple I have a basic example which I did for another poster a few weeks back
http://flashhub.net/filter/ - source is included
So your filter would look something like this, you could hard code the value in but it is always better to use variables so that any part of your program can alter the filter requirements.
                        private var minPopulation: int = 500;  <=== global variable
            protected function arrColl_filterFunc(item:Object):Boolean
                    if (item.pop > minPopulation)               
                        return true    
                    else
                        return false;