StataTex Blog

When dealing with string variables in Stata, blanks spaces can make it difficult to identify values. For example, if a variable contains " Arizona", a command that contains an if command such as ... if state="Arizona" won’t detect this observation.

To trim blank spaces (ASCII space character char(32)) at the beginning or the end of the value, Stata has different built-in functions:

* Removes blanks at beginning and end
replace state=trim(state)
* Removes blanks at beginning only
replace state=ltrim(state)
* Removes blanks at end only
replace state=rtrim(state)
* Removes all blanks in string (irrespective of place)
replace state=subinstr(state," ","",.)

To also remove other blank spaces (eg horizontal tabs), please use the ustr functions which also remove ASCII codes char(9), char(10), char(11), char(12), and char(13):

* Removes blanks at beginning and end
replace state=ustrtrim(state)
* Removes blanks at beginning only
replace state=ustrltrim(state)
* Removes blanks at end only
replace state=ustrrtrim(state)