Dear Statalist,

I hope this finds you well - my first post so please be gentle.
I regularly use data-sets which contain a very methodical naming convention and I'm trying to write some script to combine them.

The naming convention is variable_e1_c1 (incomplete observations 1-10), variable_e1_c2 (incomplete observations 11-20), variable_e1_c3 (incomplete observations 21-30), variable_e1_c4 (incomplete observations 31-40) where the variables in the data set I want to combine will all contain the same variable-name_e-number. I've started with a few approaches, however, I don't know how to pass the variable name into logical test after running say:

- ds, has(varl *_e1*).
If varname == "*_c*" {then do}.

I've also tried the approach with:

- foreach x of varlist *_e2_* {

but again I'm lost as to how to apply logic gates to the value of `x' as it takes the value of the first observation where .

Ultimately I'm keen on generating a new variable where all the observations take a similar convention and I currently use the tedious approach of copy and paste a few lines of code as such:

gen Bar=.
replace Bar= real(biadlyn_e1_c1) if biadlyn_e1_c2==.
replace Bar= biadlyn_e1_c2 if real(biadlyn_e1_c1)==.

I apologies is this thread has been covered and would appreciate a link and also do note although I'm not new to programming I am new to STATA and it's handling power so any advice would be most welcome.

Kind regards