# Optimize list combined

**URL:** <https://forum.dynamobim.com/t/optimize-list-combined/1629>\
**Category:** Packages\
**Created:** [June 15, 2015, 7:50am UTC](https://forum.dynamobim.com/t/optimize-list-combined/1629 "2015-06-15T07:50:50Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Palle\_Bisgaard](https://avatars.discourse-cdn.com/v4/letter/p/f9ae1b/32.png) [@Palle\_Bisgaard](https://forum.dynamobim.com/u/Palle_Bisgaard)\
**Post date:** [June 15, 2015, 7:50am UTC](https://forum.dynamobim.com/t/optimize-list-combined/1629/1 "2015-06-15T07:50:50Z")

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Hi all Dynamo heroes

I got an issue about list. Combined. What I want it do is, to combine the value from different list to one value.

fx:

List 0

[0] A

[1]B

List 1

[0] A

[1]

Gets into

List 0

[0] AA

[1]B

&nbsp;

It works ok with two list´s but with more, it only shows “null”

I make an example here [Intersection](http://dynamobim.com/wp-content/uploads/forum-assets/palle-bisgaardbetechdata-com/06/15/Intersection.dyn), where I have solved the issue by combined the list combined, after east odder.

Hope you can help me to optimize my scripts, so that it takes less processer power to run.

Thanks for your help.

Best regards Palle

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**Author:** ![Dimitar\_Venkov](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/dimitar_venkov/32/2068_2.png) [@Dimitar\_Venkov](https://forum.dynamobim.com/u/Dimitar_Venkov)\
**Post date:** [June 15, 2015, 9:23pm UTC](https://forum.dynamobim.com/t/optimize-list-combined/1629/2 "2015-06-15T21:23:13Z")

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Hi Palle,

In your graph you’re using “String.Insert”, which after specifying the index takes only 2 inputs.

“List.Combine” can’t map three lists to just two inputs. Have you considered using “String.Concat” instead?

![2015-06-16_10-43-18](https://cdck-file-uploads-us1.s3.dualstack.us-west-2.amazonaws.com/flex022/uploads/dynamobim/original/2X/b/bfae2ac5b9c8726014b6b35fcba12392ef8ff0ae.png)

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<div class="post-metadata">

**Author:** ![Palle\_Bisgaard](https://avatars.discourse-cdn.com/v4/letter/p/f9ae1b/32.png) [@Palle\_Bisgaard](https://forum.dynamobim.com/u/Palle_Bisgaard)\
**Post date:** [June 16, 2015, 3:27am UTC](https://forum.dynamobim.com/t/optimize-list-combined/1629/3 "2015-06-16T03:27:47Z")

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Thanks Dimitar

That helped, the script are know mush faster.

&nbsp;