Extract string between /

Question

If I have these strings:

mystrings <- c(\"X2/D2/F4\",
               \"X10/D9/F4\",
               \"X3/D22/F4\",
               \"X9/D22/F9\")

Answer 1

as.numeric(gsub("^.*D([0-9]+).*$", "\\1", mystrings))