Extracting letters from a string

[Shikasta Persson]

Hello!

I want to generate a new string variable from an old string variable that consists of everything except the last letter.

Consider the following example where I want to generate a new variable where the word is in singular instead of plural.


string1 | string2

balls | ball
tables | table
rings | ring


How do I go from string1 to string2?

I have tried substr(), but it haven't been able to make it work since it doesn't count backwards, or does it?


Shikasta

[Nick Cox]

gen string2 = substr(string1, 1, length(string1) - 1)

substr() certainly can count backwards, but in this case I don't see that would help you much. You still want to start at the beginning and the second argument of substr() is a length, not a position.

. di substr("Stata shines", -6, 6)
shines

Too devious by half is

 
reverse(substr(reverse(string1), 2, .)))

[Shikasta Persson]

Thank you Nick!

The answer was simple! Using the length of the word instead of a position.