topic Re: Arcade script to add unique value for duplicate field entries in ArcGIS Arcade Questions

Arcade script to add unique value for duplicate field entries

JustinBernard1886 — Thu, 12 Mar 2026 14:14:14 GMT

Hi everyone,

I am casual user of arcade scripting and I wonder if anyone can help me with some script?

I have a simple script where when someone enters a value into a field, the script will populate another field with "1" at the end.

What I need help with is when someone enters the same value again, I would like the duplicate value to have a "2" and increase for every subsequent duplicate value.

Here is the script that I wrote initially.

var FieldName = $feature.StopID_text;
return Concatenate ($feature.StopID_text + "-" + "BB" + "-" + "1") ;

Thanks for the help!

Cheers,

Justin

Re: Arcade script to add unique value for duplicate field entries

AlfredBaldenweck — Thu, 12 Mar 2026 15:51:44 GMT

Basically you need to get a list of everything already in Field2.

Fair warning, this is my second time on this. The first time I crashed Pro when I added a new record and had to rewrite. Idk why but the rewritten version seems to work just fine.

// Get list of all the current values in Field var self = FeatureSetByName($datastore, "test") var field2List = [] for (var s in self){ Push(field2List, s["Field2"]) } // Create a counter and your output string var counter = 1 var out = Concatenate($feature.Field1, "-BB-", counter) // Be careful with the while loops. // Had to nuke Pro twice because I got stuck forever while writing this. // No getting stuck on deployment, though while (Includes(field2List, out)){ // Update counter and the output so you can escape the loop. counter+=1 out = Concatenate($feature.Field1, "-BB-", counter) } // Return the output return out

Re: Arcade script to add unique value for duplicate field entries

KenBuja — Thu, 12 Mar 2026 15:25:39 GMT

I was looking at it another way, incrementing the counter for the unique values of `${$feature.Field1}-BB-`

I haven't tested it, but was thinking along these lines

In line 3, the FeatureSet is filtered to only show the existing values for that field. If there aren't any, it returns the string with the counter = 1 in line 4.

Lines 6-9 create a list of the values in Field2. Lines 11-15 are a reverse sorting function (taken from the Sort example) to get the highest value in line 17. Line 18 returns the string and the highest value incremented by one.

Re: Arcade script to add unique value for duplicate field entries

JustinBernard1886 — Thu, 12 Mar 2026 19:00:41 GMT

Thanks so much guys!

I'll try both out and let you know how it goes.

Re: Arcade script to add unique value for duplicate field entries

AlfredBaldenweck — Thu, 12 Mar 2026 19:09:08 GMT

I'd be interested in finding out how our two methods compare, performance-wise. I think yours may scale better?

Re: Arcade script to add unique value for duplicate field entries

JustinBernard1886 — Fri, 13 Mar 2026 11:40:47 GMT

All right,

I;m trying the second code, and I am getting a "invalid where clause." on Line 4.

Here is the code:

var fs = FeatureSetByName($datastore, "GIS_Miway_LandingPad");
var sql = `${$feature.StopID_text}-LP-`;
var filtered = Filter(fs, "LIKE AssetID @sql");
if (Count(filtered) == 0) return `${$feature.StopID_text}-LP-1`;

var list = [];
for (var f in filtered) {
Push(list, f["AssetID"]);
}

function reverseSort(a, b) {
if (a < b) return 1;
if (a > b) return -1;
return 0;
}

var highest = Sort(list, reverseSort)[0]
return `${$feature.StopID_text}-LP-${Number(Split(highest, "-LP-")[1])+ 1}`

Thanks,

Justin

Re: Arcade script to add unique value for duplicate field entries

KenBuja — Fri, 13 Mar 2026 13:03:02 GMT

When posting code, use the "Insert/Edit code sample" button.

The syntax is incorrect on the Filter's sqlExpression

var filtered = Filter(fs, "AssetID LIKE @sql");

Re: Arcade script to add unique value for duplicate field entries

JustinBernard1886 — Fri, 13 Mar 2026 14:54:35 GMT

Ahhh.

Thanks.

The code almost works. The field populates but returns a duplicate value.

Re: Arcade script to add unique value for duplicate field entries

KenBuja — Fri, 13 Mar 2026 16:55:23 GMT

My apologies. I forgot to add a wildcard in the sqlExpression. Here's the tested code that works

In my test data, I used the Habitat field

Re: Arcade script to add unique value for duplicate field entries

JustinBernard1886 — Mon, 16 Mar 2026 11:11:30 GMT

That works!

Thank you so much Ken! ❤️