Field Calculator for not null fields

[AndrewIngall1]

I am trying to use the field calculator to concatenate various fields into one new field.  The ArcGIS Arcade Guide gives the following example

Concatenate(['red', 'blue', 'green'], '/')

which gives red/blue/green.  This works fine when all of the fields contain a value, but how can i concatenate only the fields that are not null

I am trying to concatenate address details , so for example 

field1 = building name

field2 = building number

field3 = road name

field4 = area

field5 = town

in my example the building name or area could be null, so i end up with:-

,12,A Road,,Town - so i need to remove the additional field separators ','

Thanks for any help

[DanPatterson_Retired]

Arcade... no, someone else can translate this example from python

# ---- pretend data, representing field values

field1 = 'building name'
field2 =  None
field3 = 'road name'
field4 = None
field5 = 'town'

# --- put them into a list... you could put the whole list in, I just simplied it

flds = [field1, field2, field3, field4, field5]

", ".join([i for i in flds if i is not None])

# ---- result

'building name, road name, town'‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[MichaelVolz]

Dan:

In your python example, is None actually Null or some other way of showing empty data?

[JoshuaBixby]

SQL Null gets mapped to Python None in cursors and the Field Calculator, so one can use Python None to test how SQL Null will behave with a code snippet.

[KoryKramer]

Andrew Ingall‌ Did Dan's reply give you what you needed?  If so, could you mark this as answered - maybe share back how you did this in Arcade?  

If not, we should try to get an answer posted here.  I know Xander Bakker‌ is handy with Arcade!

[AndrewIngall1]

@Kory Kramer - I actually went down the FME route to concatenate the field together - I could not get my head around how to do it in ArcGIS Pro with Arcade.

[XanderBakker · Accepted solution]

Just for future reference, you could use something like this in Arcade next time:

// replace the field names according to your data
var field1 = $feature["field1"];
var field2 = $feature["field2"];
var field3 = $feature["field3"];
var field4 = $feature["field4"];
var field5 = $feature["field5"];

var fields_in = [field1, field2, field3, field4, field5];
var fields_out = [];
for (var i = 0; i < Count(fields_in); i++) { 
    if (fields_in[i] != Null) {
        var j = Count(fields_out);
        fields_out[j] = fields_in[i];
    }
}

var label = Concatenate(fields_out, "/");
return label;‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

This will only omit Null values and not empty strings. 

I know Dan, this is much longer than the Python snippet you provided... 

[DanPatterson_Retired]

And longer than in Avenue too

[Andra]

Hi, Xander

Thanks for the solution to this concatenation task. When i use your code in ArcGIS pro 2.9.5 field calculator tool in model builder, i am getting an error 'identifier expected' on line 17:

var field1 = $feature.utm_check;
var field2 = $feature.township_match;
var field3 = $feature.range_match;
var field4 = $feature.section_match;
var field5 = $feature.DPA_match;
var field6 = $feature.county_match;

var fields_in = [field1, field2, field3, field4, field5, field6];
var fields_out = [];
for (var i = 0; i < Count(fields_in); i++) { 
    if (fields_in[i] != Null) {
        var j = Count(fields_out);
        fields_out[j] = fields_in[i];
    }
}

var label = Concatenate(fields_out, ",");
return label;‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Can you provide any guidance on this syntax error please? 

thanks, a

[Andra]

Update - I was able to use Dan's python suggestion to concatenate the fields, but i am still curious about the above error if there is a simple solution. thanks!

', '.join([str(i) for i in [ !utm_check!, !township_match!, !range_match!, !section_match!, !DPA_match!, !county_match!] if i])

-a