Comments on: ActionScript 3 Remove duplicates in an array

By: Mat G

Mat G — Sun, 24 Jan 2010 22:55:31 +0000

Hi guys just though id throw a slightly different approach into the mix..

function removeDuplicates(array:Array):Array
{
var tempRef:Dictionary = new Dictionary();
var newArray:Array = [];
var i:int = array.length;
var tempItem:*;

while(i–)
{
tempItem = array[i]

if(!tempRef[tempItem])
{
tempRef[tempItem] = true;
newArray.push(tempItem);
}
}

return newArray;
}

By: Martin Burke

Martin Burke — Fri, 22 Jan 2010 15:19:41 +0000

I was having the same problem, where if I had something repeated more than once, only 1 got removed. This can simple be fixe dby replacing the "if" with a "while". With an input of ["a","a","b","b","c","c","a","a","d","d","e","e"]; if (ac[i] === ac[j]) gives and output of "a,b,c,a,d,e" (wrong!) while (ac[i] === ac[j]) gives an output of "a,b,c,d,e" (correct!) The while forces a check on the new element which has shifted into the position which has just been deleted

By: Matthieu Chavigny

Matthieu Chavigny — Thu, 17 Dec 2009 14:53:17 +0000

public static function unique(a:Array):Array
{
var n:Array = new Array();
for each(var e in a) {
var o:Boolean = false;
for each(var ne in n) if (ne == e) o=true;
if(!o) n.push(e);
}
return n;
}

By: Bruno Fenzl

Bruno Fenzl — Sun, 25 Oct 2009 20:52:58 +0000

@Brian
your code is simple and very efficient. Great!!!! thanks.

@all
Thanks for the wonderful examples of logic.

By: Tim

Tim — Tue, 21 Jul 2009 07:06:02 +0000

This is the version I just made up:

array.forEach( removeDups );
function removeDups( value:*, index:int, arr:Array):void {
for( var i:Number = 0; i < arr.length; i++ ) if( i != index ) if( value === arr[i] ) arr.splice( i, 1 );
}

By: Xavier Laumonier

Xavier Laumonier — Wed, 03 Jun 2009 08:48:07 +0000

Hi !

Good function, but it should be :

var length:int = ac.length
for (i = 0; i < length – 1; i++)
for (j = i + 1; j < length ; j++)

it will be much more optimized, because the length of the array is computed one time in this version, but in your version, the length of the array is computed ( 2 * array.length – 1 ) times..

By: bubbleboy

bubbleboy — Thu, 14 May 2009 19:09:47 +0000

just what i was looking for! thanks a lot!

By: Trickmaster

Trickmaster — Tue, 24 Mar 2009 20:43:25 +0000

Hey thanks a bunch! i tried this code yesterday didn’t work since I had 4 same values in my array, and it only got rid of 2 of them. Then I looked at Quince’s comment today and I retried the code and it worked like a charm!

Thanks a bunch man

By: mauro

mauro — Sun, 04 Jan 2009 14:43:01 +0000

Sorry guys, I am interested in using this code, but which one is best for checking duplicates in matter of emails?

The array to be a list of emails.

I have done a script(*) to get rid of almost every dirt from copy and paste from CSV, XLS, Outlook, and other common tools.

Now I would like to get rid of duplicates!

(*)Here is the source code:
http://www.vacanzecroate.com/careless/email/ciclo_CommaEmails_fromTAB.html

By: brian

brian — Fri, 24 Oct 2008 23:40:49 +0000

don’t forget closures in as 3.

var is_unique:Function = function (item:*, index:int, array:Array):Boolean {
return array.indexOf(item,index + 1) == -1;
};

var array = [1,2,1,3,2,3];
trace(array.filter(is_unique));