generate variable indicating variable name where observation is not missing

[Franziska Hittmair]

Hello,
in my dataset i have several variables which either have the value of 1 or are missing. For every row there is only one variable where the value is 1 and not missing.
I want to create a new variable now, that indicates the variable name of the variable that is NOT missing.

this is an example of my data:

* Example generated by -dataex-. For more info, type help dataex
clear
input float(Firm94 Firm121 Firm133 Firm241 Firm246 Firm301 Firm478 Firm499 Firm522 Firm590 Firm731 Firm742 Firm1310 Firm1672 Firm1843 Firm1910)
1 . . . . . . . . . . . . . . .
1 . . . . . . . . . . . . . . .
1 . . . . . . . . . . . . . . .
. 1 . . . . . . 1 . . . . . . .
1 . . . . . . . . . . . . . . .
1 . . . . . . . . . . . . . . .
. . . . 1 . . . . . . . . . . .
1 . . . . . . . . . . . . . . .
1 . . . . . . . . . . . . . . .
1 . . . . . . . . . . . . . . .
end

now i would like to have a variable, for example called "Firm", as a string that writes Firm94 in first, second, third row, Firm121 in fourth row and so on.
At first i thought this should be pretty straight forward but i somehow cannot wrap my head around it.
Can someone help me with this ?
thank you in advance !

[Daniel Schaefer]

What about something like this?

gen newvar = .
foreach num in 94 121 133 241 246 301 478 499 522 590 731 42 1310 1672 1843 1910{
    replace newvar = Firm`num' if Firm`num' == 1
}

I haven't tested this since I am not at a computer with Stata installed, but I think it should work.

[Daniel Schaefer]

Actually, just thinking about it, you might need to surround the first Firm`num' in quotes to make sure it is interpreted as a string.

replace newvar = "Firm`num'" if Firm`num' == 1

[Andrew Musau]

gen wanted=""
foreach var of varlist Firm*{
    replace wanted= "`var'" if missing(wanted) & `var'==1
}

[Franziska Hittmair]

Andrew, that worked perfectly. thank you !