Arcade expression to count related table

TKSHEP

I am looking for help on creating an expression to count the number of related features using (example) 1 of # number of related to feature. ex 1 of 3 (next feature shows) 2of 3 and then 3 of 3.  

Any help would be greatly appreciated. 

Thank you!

jcarlson

Knowing what the data looks like would help, but using FeatureSetByRelationshipName is the best way to quickly grab related records, if there's a legitimate relationship between the tables.

Is this for a popup? Field calculation? Dashboard?

var rel = FeatureSetByRelationshipName($feature, 'relationshipname', ['field1', 'field2', 'field3'], false)

// count of related features
var the_count = Count(rel)

// build a popup out of related feature info
var popup_arr = []
var feat_idx = 1

for (var r in rel) {
  Push(popup_arr, `Feature ${feat_idx} of ${the_count}:
    Field One: ${r['field1']}
    Field Two: ${r['field2']}
    Field Three: ${r['field3']}`
  )
  feat_idx += 1
}

return Concatenate(popup_arr, '\n\n')

Depending on where you're trying to use this expression, you may need HTML line breaks instead of \n, but try this out and see how it works.