Another concat formula issue-- why won't it run?

[deleted-user-57QLt_-7NcdX]

Hi,

I'm having problems getting a concat function to combine three variables so I can move onto a pulldata() function.

In Line29 of the attached Survey123 XLSForm, I can get the concat function to run with the first two variables (e.g., concat(${Shade} , '_', string(${maxRFMTemp2}))), however, when I add the third variable, which is critical for the subsequent pulldata() function, the process dies (e.g. concat(${Shade} , '_', string(${maxRFMTemp2},'_',string(${FDFM2})))).

FWIW, I expect the pulldata() function in the following line will be: 

pulldata("ProbabilityOfIgnition", "PIG", "Code", ${lookupCode3})

Thanks for any help.

Best,

Scott

[JamesTedrick · Accepted solution]

There looks to have been a small issue with the lookupCode3 question- the was a  missed parenthesis:

concat(${Shade} , '_', string(${maxRFMTemp2}), '_', string(${FDFM2}))

[deleted-user-57QLt_-7NcdX]

Thanks James, I knew it had to be embarrassingly simple.  That said, understanding what exactly the "string" call is doing remains a mystery to me.  For example, other concat functions I've used worked fine without the use of that mid-function end-parenthesis.  Regardless, thanks for the catch!

[JamesTedrick]

Hi Scott,

The string() function converts an answer of another type (integer or decimal) into text so that it can be concatenated together.  This is perhaps more understandable when using '+' instead of concat (which, in the mobile app, does the same thing for text as concat):

(Numbers): 5 + 5 = 10

(Text): "5" + 5 = "55" (the second 5 is auto-converted to text and then concatenated together)

(Numbers converted): string(5) + 5 = "55" (the first 5 is made text, and then concatenated with an auto-converted second 5)

All of the above work in the mobile application; it's somewhat permissive in automatically conversion The new webform we are releasing is not permissive and requires explicit conversion.