I then have a slider that I want to use as a selector for the letters and a text box which shows which letter has been selected. So in the slider logic, I have this but when I run it I get an error that Alphabet2 is undefined.
Have you tried debugging the logic to see what values are actually there? For example, when you use the print block, it will output its value into the Console tab of the browser’s DevTools panel.
The On Change Event is for the slider (logic shown above). If I have only the first set block enable, and do a print on Alphabet2, I get an empty array.
When I enable the second set block, I get an response of undefined.
APP ID is 4F8308C4-61AE-488A-8E12-F7C47377AAF4, Default Container, landing page if you want to see first hand.
When you assign (or read) a value in PageData (or any other data model/object), you have to reference properties as strings. In your case you reference a property by providing an empty list. That doesn’t make sense and will not work.