stringr str_extract capture group capturing everything

Question

I\'m looking to extract the year from a string. This always comes after an \'X\' and before \".\" then a string of other characters.

Using stringr\'s

Answer 1

Alternatively, you can use gsub:

string = 'X2015.XML.Outgoing.pounds..millions.'

gsub("X(\\d{4})\\..*", "\\1", string)
# [1] "2015"

or str_replace from stringr:

library(stringr)
str_replace(string, "X(\\d{4})\\..*", "\\1")
# [1] "2015"