ArcGIS Pro: Field Calculator & Text Manipulation Using Arcade

How can I use 'Count' function using arcade to count each row from a column?

If I do return new[2] I get an error since not all my rows have 2 values. How do I get around this?

Hi. Thanks for sharing. Is it possible to add subtypes values using field calculator?

Thanks, helped me a lot. I did it selecting all attribute table, because in the normal way it wasn't work.