Use an array of strings as ComboBox data source
<?xml version="1.0"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:ComboBox labelField="state"> <mx:ArrayCollection> <mx:Object state="A" capital="aa" /> <mx:Object state="B" capital="bb" /> <mx:Object state="C" capital="cc" /> </mx:ArrayCollection> </mx:ComboBox> </mx:Application>