Are you trying to compare two Arrays as sets, where [ 1, 3, 2, 1 ] and [ 1, 1, 2, 3 ] are considered the same? If so, I would sort() them -- which I would expect to take only O(n ln n) -- and then compare them element by element until you found a mismatch or reached the end. Avoid using anonymous functions. My understanding is that they don't perform as well as class methods because they require an activation frame. Gordon Smith Adobe Flex SDK Team
________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Maciek Sakrejda Sent: Friday, February 22, 2008 9:23 AM To: [email protected] Subject: Re: [flexcoders] What is the best way to compare two arrayselement by element ignoring the order? Extra points for higher-order function, although that is going to be O(n^2) (unless Array.indexOf() has a weird implementation). If you've got really, really big arrays (or are doing this in a tight loop) and you have O(n) memory to spare, you could consider building a hashmap of the values in Array a, and then walking Array b and checking if each element is in the hashmap: var differs:Boolean = (a.length != b.length); if (!differs) { var aContents = new Object(); a.forEach(function(item:Object, index:int, array:Array):void { aContents[item] = true; }); differs = b.some(function(item:Object, index:int, array:Array):Boolean { return aContents[item] == null; }); } For small-ish arrays, though, I would expect your solution to be faster than mine (I won't define 'small-ish', since I would honestly be pulling a number out of my--err, out of thin air). Also, neither your solution nor mine handles the case where the same item is in one array twice (yours fails for dupes in a and mine for dupes in b). -- Maciek Sakrejda Truviso, Inc. http://www.truviso.com <http://www.truviso.com> -----Original Message----- From: Sergey Kovalyov <[EMAIL PROTECTED] <mailto:skovalyov.flexcoders%40gmail.com> > Reply-To: [email protected] <mailto:flexcoders%40yahoogroups.com> To: [email protected] <mailto:flexcoders%40yahoogroups.com> Subject: [flexcoders] What is the best way to compare two arrays element by element ignoring the order? Date: Fri, 22 Feb 2008 15:37:56 +0200 What is the best way to compare two arrays element by element ignoring the order? My solution: var differs : Boolean = (a.length != b.length) || a.some( function(item : Object, index : int, array : Array) : Boolean { return (b.indexOf(item) == -1); }); May be the better solution exists?
