Array.map

This was a lifesaver for me. Array.map will run a function on every item of an array and construct a new array based on what is returned from the function call. I don’t have a demo, but this is from Adobe:

package {
    import flash.display.Sprite;
    public class Array_map extends Sprite {
        public function Array_map() {
            var arr:Array = new Array("one", "two", "Three");
            trace(arr); // one,two,Three

            var upperArr:Array = arr.map(toUpper);
            trace(upperArr); // ONE,TWO,THREE
        }
        private function toUpper(element:*, index:int, arr:Array):String {
            return String(element).toUpperCase();
        }
    }
}