Repeating Arrays

[tellis]

Hey all, 

I'm trying to make it where this block has alternating patterns so as you drag the arrow it'll show one then the other as you go along. I've looked on the forums and the one's I've seen a slightly differently and it's enough I'm coming up short. Can some one try explaining or showing me how to do this? I can do the basics of making both array at the same time but getting it to alternate is my struggle. 

Thanks

[Libbya · Accepted solution]

The important point to know is that the array adds the first new object when the linear parameter is equal to 2X the column offset.  See screencast.

[tellis]

Thank you! This was amazing to see how it was done. Since posting I managed to get 80% the way there but the final 20% was a huge help. Thank you!