for each

var mc1:MovieClip = new MovieClip();
mc1.name = 'material';
var mc2:MovieClip = new MovieClip();
mc2.name = 'furniture';
var mc3:MovieClip = new MovieClip();
mc3.name = 'instant';
var obj:Object = {
     material: mc1,
     furniture:mc2,
     instant:mc3
};
trace('--------------------------------------');
for (var key:String in obj)
{
     trace(obj[key]);
     trace(key);
}
/*
[object MovieClip]
furniture
[object MovieClip]
instant
[object MovieClip]
material
*/
trace('obj[item]--------------------------------------');
for each(var item:String in obj)
{
     trace(item);
}
/*
[object MovieClip]
[object MovieClip]
[object MovieClip]
*/
trace('elementがobjになる--------------------------------------');
for each(var element:Object in obj)
{
     trace(element);
}
/*
[object MovieClip]
[object MovieClip]
[object MovieClip]
*/