Problem with locals

[Christopher Weare]

Minor but annoying problem with locals. I have a long variable list that I would like to add to a file with the following code. I keep on getting errors for invalid syntax and too few variables specified. I have not been able to find a fix to the code. Any suggestions

local vars "site_visits_with_case_worker Indoor_Bathroom Porta_Potty washing_Station ADA_Compliant_Shower"

local num: word count `vars'

foreach i in 1/`num' {
local temp `: word `i' of `vars''
di `temp'
gen `temp' = .
}

[Nick Cox]

The first bug I can see in this code is that while

foreach i in 1/`num' {

is legal, it is not at all what you want. because

1/`num'

is taken as a single item and when substituted as

local temp `: word 1/`num'  of `vars''

it is then illegal.

You probably meant something more like

foreach i of numlist 1/`num'

which in turn would be better as

forval i = 1/`num'

but looping over numbers is needless here as the real problem is looping over some names, which you can do directly.

I would try

 
local vars "site_visits_with_case_worker Indoor_Bathroom Porta_Potty washing_Station ADA_Compliant_Shower"

foreach v in `vars' { 
    di "`v'" 
    gen `v' = . 
}

[Christopher Weare]

Thank you! What would you suggest as a good source to teach myself more about these subleties?

[Bruce Weaver]

The University of Wisconsin-Madison has some nice resources you might find helpful. Expand the Data Wrangling section on this page, and take a look at the pages for Stata Programming Essentials and Stata Programming Tools. HTH.

[Nick Cox]

#3 Modesty aside, https://journals.sagepub.com/doi/pdf...36867X20976340 was a 2020 rewrite of a 2002 tutorial introduction to loops.

As for whether it is best for you, I can't possibly comment!