Google Apps Script Tutorial: Checking Values Against An Array - Prevent Data Duplication

I've received a lot of comments on previous videos asking how to prevent data duplication when working with Apps Script. In this video I show you a few ways to build and use arrays of values to check against when sorting through data.
You can see the code I wrote in this video here - gist.github.co...

[@danbrown1117]

Awesome, great explanation as well. Thank you!

[@jsphpalumbo]

You're very welcome!

[@coordinadoru.g.a.9846]

Gracias desde venezuela, Thank you very much!!! Me va a ser de mucha utilidad este concepto. que estes bien¡

[@tpp-dw1ps]

thank you bro .....

[@bulbulahmed3098]

❤❤❤

[@anthonysaunders476]

Can you do a video on how to compare data from a dynamic sheet (can remove rows or add rows daily) to data on a static sheet (should never delete rows) , then append data on the dynamic sheet that is not on the static sheet to the last row on the static sheet? Hopefully what I'm asking is clear.

[@pichit.raetai]

Thank you😀

[@douglasteixeiradeabreu]

Gostei do jeito que você explicou

[@rohitkumawat6416]

Hello,
Can you help me with this query?
I have a google sheet named mastersheet and 10 copies of this mastersheet now I want to rename column name in mastersheet and it should be update in all 10 copied sheets automatically using app script, if it is possible then please make a video.
How can I do that?

[@timothykwok1435]

Returns null for me? :/