remove information using gsub

Question

I am trying to remove all the information up to the last / (the year) from this line.

"'CSF0495/DE/wb/1997'"

The code I run goes through but does not remove any information.

This it the code I run

date <- gsub("^[[:alnum:]]{1,}////", "",temp)

It goes through, but does not remove any information. Im not sure what I am missing.

Answer 1

Using sub

sub(".*/", "", "CSF0495/DE/wb/1997")
[1] "1997"

---

Or with basename

basename("CSF0495/DE/wb/1997")
[1] "1997"

Answer 2

Why not simply extract the year, knowing that it consists of more than one digits extending as far as final position in string ($)?

library(stringr)
str_extract("CSF0495/DE/wb/1997", "\\d+$")
[1] "1997"