remove last letters in a word

[River Huang]

Dear All, The data set is

* Example generated by -dataex-. To install: ssc install dataex
clear
input str10 var
"ACAC"
"BAC" 
"GAC" 
end

How can I remove the last AC from all words to obtain

* Example generated by -dataex-. To install: ssc install dataex
clear
input str10 var
"AC"
"B" 
"G" 
end

Thanks for your suggestions.

[River Huang]

Dear Leonardo, Thanks for this suggestion. I also learned (from others) another approach

* Example generated by -dataex-. To install: ssc install dataex
clear
input str10 var
"ACAC"
"BAC" 
"GAC" 
"NASD"
end

gen wanted=ustrregexra(var,"AC$","")

[Leonardo Guizzetti]

This is actually well suited for regular expressions. The pattern looks to see if "AC" is at the end of the string, and returns the part before the match. The string is left untouched if there is no match. Here I'm using a case-insensitive match, as determined by the last argument to -ustrregexm()-.

clonevar want = have
replace want = ustrregexs(1) if ustrregexm(want, "(.*)(AC)$", .)

Result:

     +-------------+
     | have   want |
     |-------------|
  1. | ACAC     AC |
  2. |  BAC      B |
  3. |  GAC      G |
  4. | NASD   NASD |
     +-------------+

[River Huang]

Dear Ali, Thanks a lot. It helps.

[Ali Atia]

replace var = substr(var,1,strlen(var)-2) if substr(var,strlen(var)-1,2) == "AC"