how to catch the last number in a sentence?

Question

for example:

'I want to get 10 apples, 99 bananas and 86 oranges.'

'I want to buy a car'

What I want to do is get the last number in the sentence. The result I m hoping is:

86

NA

How can I make it possible by using R? thanks~

p.s. I just want to catch Arabic numerals

score 5 · Answer 1 · answered May 02 '19 at 14:54

5

Using stringi we can use stri_extract_last_regex which will return last matched pattern in the string.

as.numeric(stringi::stri_extract_last_regex(x, "\\d+"))
#[1] 86 NA

data

x <- c('I want to get 10 apples, 99 bananas and 86 oranges', 'I want to buy a car')

answered May 02 '19 at 14:54

Ronak Shah

What if my data is a data.frame? – recon May 02 '19 at 14:59
@recon instead of `x` use the column name then. `df$column_name`. – Ronak Shah May 02 '19 at 15:00
thank you for your reply mate but sorry that i think i should accept the answer by @akrun because he answer me first. sorry again mate. – recon May 02 '19 at 15:05
@recon no issues, you can accept any answer of your choice :) – Ronak Shah May 02 '19 at 15:15

score 3 · Accepted Answer · edited Jun 20 '20 at 09:12

3

We can use str_extract from stringr which is also based on tidyverse

library(stringr)
as.numeric(sapply(str_extract_all(str1, "\\d+"), tail, 1))
#[1] 86 NA

Or just using only base R

as.numeric(sub(".* (\\d+).*", "\\1", str1))
#[1] 86 NA

If it is a data.frame, we extract the column and update the columns

df1$col1 <- as.numeric(sapply(str_extract_all(df1$col1, "\\d+"), tail, 1))

Also, we can find more resources from this link

str1 <- c("I want to get 10 apples, 99 bananas and 86 oranges.",
    "I want to buy a car")

edited Jun 20 '20 at 09:12

Community

answered May 02 '19 at 14:52

akrun

2 Answers2