I have 9 columns, each with the header 1-9. I want to iterate across each row, and if value exists in a particular column, I would like to grab the header value (1-9) and concatenate it as a comma separated array.
Then, I would like to be able to use an arrayformula to display each of these arrays vertically—one per row—without having to copy paste my formula to each row.
Here's what I have so far:=ArrayFormula(IF($C$2:$C>0,IFERROR(JOIN(",",(FILTER(INDIRECT("N"&ROW()):INDIRECT("V"&ROW()),INDIRECT("N"&ROW()):INDIRECT("V"&ROW())<>""))),""),""))
The formula works perfectly if I paste it into every row (without arrayformula). However, if I use arrayformula it only outputs the value of the first row (but only to the rows that have values—it remains empty if there are no values).