Remove only multiple brackets

Question

I have string in this form

"[1425]", "[[12545]]", "2423", "((125))", "[[[1543]]]", "(1432)"

I tried the solutions in the link, but it is not working for this case. I need

"[1425]", "[12545]", "2423", "(125)", "[1543]", "(1432)" 

ie. remove the multiples of bracket present.

Answer 1

Try:

library(stringr)
v1 <- c("[1425]", "[[12545]]", "2423", "((125))", "[[[1543]]]", "(1432)")

str_extract(v1, "\\D?[0-9]+\\D?")
#[1] "[1425]"  "[12545]" "2423"    "(125)"   "[1543]"  "(1432)" 

Answer 2

And the award for most unreadable answer goes to:

x <- c("[1425]", "[[12545]]", "2423", "((125))", "[[[1543]]]", "(1432)")
gsub("(\\[|\\]|\\(|\\))\\1+","\\1",x)
#[1] "[1425]"  "[12545]" "2423"    "(125)"   "[1543]"  "(1432)"