as3去除数组中的相同成员

var arr:Array=[“aa”,”bb”,”cc”,”dd”,”bb”,”cc”,”aa”,”bb”,”gg”,”aa”,”cc”];
function formatX(arr:Array):Array {
var obj:Object={};
return arr.filter(function(item:*, index:int, array:Array):Boolean{return !obj[item]?obj[item]=true:false});
}
trace(formatX(arr));