Question

package
{
    import flash.display.Sprite;
    import flash.media.Sound;
    import flash.media.SoundChannel;

    public class EmbeddedSoundExample extends Sprite
    {
        [Embed(source="smallSound.mp3")]
        public var soundClass:Class;

        public function EmbeddedSoundExample()
        {
          //WHAT DOES "as" keyword DO IN THE FOLLOWING LINE ??
          //*************************************************

            var smallSound:Sound = new soundClass() as Sound;

            //COULD BE WRITTEN AS : 
            //==>>>> var smallSound:Sound = new soundClass() ???
            // OR
            ////==>>>> var smallSound:Sound = new Sound() ???
         //******************************************************

            smallSound.play();
        }
    }
}

Answer 1

This is a casting operator introduced in ActionScript 3. The difference with as (as opposed to Type(object) casting) is that if the cast fails, the result will be the default value for the type. More on this here