vr button array to switch materials of objects

My aim is to be able to manipulate the material of a room with a button.
I want to show 4 different materials an switch through them with a “forward” an a “backwards” button on the wall.
With a tutorial I made a switch that moves a block and reacts to the VR Player and my next step is to put the different materials in an array and make the button switch the current position of the array.
But I can’t find any tutorial that helps my setting this up, maybe it’s super easy and I don’t quite get it.

How do I connect the different materials to the array?
How do I Implement the array to the button?

The screenshot shows the blueprint of my button so far

Hi there! You can always do

  1. Add property and set it as array
  2. Use MakeArray pnode, connect one to define the type and after that you can select values from lists