http://stackoverflow.com/questions/15274460/how-delete-duplicate-values-in-array-actionscript3

ArrayDuplicates.as

package arrayDuplicates
{
    import flash.utils.getTimer;

    /**
     * @author creynder
     */
    public class ArrayDuplicates{
        public function ArrayDuplicates()
        {
            
            var list : Array = generateArray();

            trace( '-- run --'  );
            var l1 : Array = list.concat();
            var t1 : Number = getTimer();
            var o1 : Array = methA( l1 );
            trace( getTimer() - t1 );
            var l2 : Array = list.concat();
            var t2 : Number = getTimer();
            var o2 : Array = methB( l2 );
            trace( getTimer() - t2 );
        }
        
        public function generateArray() : Array{
            var output : Array = [];
            var i : int;
            var n : int = 100000;
            for ( i = 0; i<n; i++ ){
                output.push( Math.floor( Math.random() * 12 ) );
            }
            return output;
        }
        
        public function methA( list : Array ) : Array{
            list = list.sort( Array.NUMERIC );
            for ( var i = list.length -1; 1 <= i; --i )
            {
                if ( list[i-1] == list[i] )
                {
                    list.splice(i-1,1);
                }
            }
            return list;
        }
        
        public function methB( list : Array ) : Array{
            return list.filter( myFilter );
        }
        
        function myFilter(element:*, index:int, arr:Array):Boolean {
            return (index==arr.lastIndexOf(element));
        }

    }
}

output.txt

-- run --
3646
161
-- run --
3696
129
-- run --
3696
129
-- run --
3968
111