Adding a character at a certain place within a string variable

[Katja Ko]

Hi everyone,

I've got a string variable ("ID") which contains a patient code. This code ist composed of the patients' 3rd letter of his/her first name, the 3rd letter of his/her last name, the date of his/her birthday and a clinic identifier.

For example: Jane Meyer, born on the 11th of November, patient in the clinic with the number 22 would have the following patient code: NY1122.
If Jane Meyer would have been born on the 8th of November, her code would be: NY0822.
However, for some patients it has been forgotten to include the "0" when the day of the birthday was single-digit. So sometimes it's: NY822.

I want to add the character "0" for these cases. So I am looking for something that says: add a 0 on the third place of the string label if the label is 5 characters long.

I am quite at loss how to do this and would really appreciate your help!

Best
Katja

[Nick Cox]

help string functions

is your friend here and indeed https://journals.sagepub.com/doi/pdf...867X1101100308 may help. (Note: StataCorp has changed the preferred function names in a few cases since that paper, but the names discussed in that paper should all work.)

replace ID = substr(ID, 1, 2) + "0" + substr(ID, 3, .) if strlen(ID) == 5

[Katja Ko]

Thank you very much!! This is the solution! :-)

[Hannah Beilby]

Hi there,

I am trying to do a similar thing but am getting an invalid syntax error, can anyone tell me why?

replace atc_code = substr(atc_code, 1) + "0" + substr(atc_code, 2, .) if strlen(atc_code) == 5

I've checked the variable is a string.. I note it works if I insert the zero in the 3rd position (per below) but I need it to be in the second.

replace atc_code = substr(atc_code, 1, 2) + "0" + substr(atc_code, 3, .) if strlen(atc_code) == 5

Many thanks,
Hannah

EDIT: Apologies - checked the help for substr - code should be

replace atc_code = substr(atc_code, 1, 1) + "0" + substr(atc_code, 2, .) if strlen(atc_code) == 5