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rstringsubstring

extract substring between "-" and "-" in string in R

i have a list of string that looks like this:

list=["chr21-10139833-A-C","chry-10139832-b-f"]

for every string in the list i need to extract the numbers between "-" and "-"

so i would get:

[10139833,10139832]

i tried this :

gsub(".*[-]([^-]+)[-]", "\\1", list

but it returns :

[ac,bf]

what can i do to make it work ? thank you

Solution

  • Using str_extract from stringr we can try:

    list <- c("chr21-10139833-A-C", "chry-10139832-b-f")
nums <- str_extract(list, "(?<=-)(\\d+)(?=-)")
nums

[1] "10139833" "10139832"

    We could also use sub for a base R option:

    list <- c("chr21-10139833-A-C", "chry-10139832-b-f")
nums <- sub(".*-(\\d+).*", "\\1", list)
nums

[1] "10139833" "10139832"