Count how many times a certain character appear in a string variable

[Antonio Garzon]

Hi,

I have been looking for a way to count the occurrence of a character in a variable, but have only found this https://www.stata.com/statalist/arch.../msg01131.html that does really answer my question.

I have a sting variable (Disease) with a certain amount of ",". I would need to create a variable (Comas) that counts the number of "," for each value. How would you go about this?

Thanks.
Best regards
Antonio

[Marcel Campion]

Hi, is there several Disease per cell? Like Cell [2;2] "Malaria, Pneumonia, HIV" ?

[Nick Cox]

The number of commas is the length of the string MINUS the length of the string should the commas be removed.

gen ncommas = length(Disease) - length(subinstr(Disease, ",", "", .))

Written up here:

SJ-11-2 dm0056 . . . . . . . Stata tip 98: Counting substrings within strings
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox
Q2/11 SJ 11(2):318--320 (no commands)
tip on counting substrings within strings

http://www.stata-journal.com/sjpdf.h...iclenum=dm0056

[Antonio Garzon]

Dear Nick,
Thanks. It makes sense!

[Tanveer Ahmad]

thanks Nick, great idea