Finding last digits in text using stringr

Question

Trying to use StringR to find all the digits which occur at the end of the text.

For example

x <- c("Africa-123-Ghana-2", "Oceania-123-Sydney-200")

and StringR operation should return

"2  200"

I believe there might be multiple methods, but what would be the best code for this?

Thanks.

yes, i tried using str_match, but i guess couldn't figure out the reverse (right to left) lookup. — mike, Jun 25 '19 at 03:40

score 2 · Accepted Answer · answered Jun 25 '19 at 03:22

2

You could use

sub(".*-(\\d+)$", "\\1", x)
#[1] "2"   "200"

Or

stringr::str_extract(x, "\\d+$")

Or

stringi::stri_extract_last_regex(x, "\\d+")

answered Jun 25 '19 at 03:22

Ronak Shah

akrun · Answer 2 · 2019-06-25T03:58:13.430

We can use regexpr/regmatches in base R to match one or more digits (\\d+) at the end ($) of the string

regmatches(x, regexpr("\\d+$", x))
#[1] "2"   "200"

Or with sub, we match characters until the last character that is not a digit and replace with blank ("")

sub(".*\\D+", "", x)
#[1] "2"   "200"

Or using strsplit

sapply(strsplit(x, "-"), tail, 1)
#[1] "2"   "200"

Or using stringr with str_match

library(stringr)
str_match(x, "(\\d+)$")[,1]
#[1] "2"   "200"

Or with str_remove

str_remove(x, ".*\\D+")
#[1] "2"   "200"

2 Answers2