"Map" function in Zoho creator / Zoho Workbook help

"Map" function in Zoho creator / Zoho Workbook help

Hello,

I'm new to Zoho creator and I'm just going through the workbook. I'm currently in the "Add Business Logic" section of the workbook and trying out "Change delivery option based on number of products selected". It does not seem to recognise the ".size()" function and returns it as an invalid syntax.

My understanding that is the "size()" is a built in map function. I need to check Product.size() where "Product" is a lookup field, but it doesn't seem to recognise it. Did I miss something? Can I assign the map function to "Product" with something like map1 = Map(); map1 = Product or something like that?

Thanks in advance!