Remove some characters from a string

[Olena Onishchenko]

Dear Stata Users

I have a string variable IssueCode. My aim is to end up with left 12 characters of this variable, for example 512KR7017170002 should become KR7017170002.

I am aware of substr function but my problem is that not all variables have the same amount of characters, I have variables such as 30KR7005560008, 507KYG5307W1015. But all I need is to take 12 left characters...

I have tried the following code but it does not work...

gen IssueCode2=substr( IssueCode ,-1, - 12)

* Example generated by -dataex-. To install: ssc install dataex
clear
input str16 IssueCode float(Price date)
"7KR7200880003"    13450 20269
"1058KR7006890008"  6150 20269
"504KR7007570005"  77100 20269
"30KR7005560008"       . 20269
"507KYG5307W1015"      .     .
end
format %tdNN/DD/CCYY date

What is the way around it?

Thank you.

[Jorrit Gosens]

Following might work, if I am right in guessing that in all cases, you want to preserve the last 12 characters of the string.
Use stringlength http://www.stata.com/manuals13/m-5st...-5strlen%28%29
and substring http://www.stata.com/manuals13/m-5substr.pdf

gen codelength = strlen(IssueCode)
gen codestartpos = codelength-11
gen IssueCode2 = substr(IssueCode, codestartpos, 12)

There may be cleaner ways, but this is simple and intuitive

[Olena Onishchenko]

Thank you Jorrit for sush a prompt response and help.

I just have tried the following, seems working...

gen IssueCode2=substr( IssueCode ,-12,12)

Hope it will serve my purpose for all cases.

[Oded Mcdossi]

Another way around is to count 12 char from the end.

 g a=substr(IssueCode,-12,.)

[Nick Cox]

Small tip. Once you know a function name you can go straight to its help by adding parentheses in a help call as in

help substr()

which in this instance documents the possibility that a negative integer can be used to indicate a position counting from the end of a string or the values of a string variable.

[Jorrit Gosens]

Right. Was unaware of that functionality of substr. That is neater.