正则表达式在某个字符串后提取数字

Question

我如何在R中提取始终位于字符串-{any single letter}之后的数字，例如来自向量：

c("JFSDLKJ-H465", "FJSLKJHSD-Y5FSDLKJ", "DFSJLKJAAA-Z3216FJJ")

应该得到：

(465, 5, 3216).

-{any single letter}模式只出现一次。

Answer 1

您可以使用gsub，例如：

x <- c("JFSDLKJ-H465", "FJSLKJHSD-Y5FSDLKJ", "DFSJLKJAAA-Z3216FJJ")
as.numeric(gsub("^.*-[A-Z]+([0-9]+).*$", "\\1", x))
# [1]  465    5 3216

Answer 2

library(stringr)
v <- c("JFSDLKJ-H465", "FJSLKJHSD-Y5FSDLKJ", "DFSJLKJAAA-Z3216FJJ")
as.numeric(sapply(str_match_all(v, "\\-[a-zA-Z]([0-9]+)"),"[")[2,])
## [1]  465    5 3216

Answer 3

> x <- c("JFSDLKJ-H465", "FJSLKJHSD-Y5FSDLKJ", "DFSJLKJAAA-Z3216FJJ")
> as.numeric(gsub("[A-Z]|-", "", x))
## [1]  465    5 3216