How to obtain character at a specific place?

Question

example:

"A.B.C.D"
"apple.good.sad.sea"
"X1.AN2.ED3.LK8"

What I need is to obtain the string specifically between the second dot and the third dot.

result:

"C"
"sad"
"ED3"

How can I do this?

score 2 · Accepted Answer · answered Oct 23 '19 at 07:21

2

You can use base::strsplit, loop thr the elements to get the 3rd one

v <- c("A.B.C.D", "apple.good.sad.sea", "X1.AN2.ED3.LK8")
sapply(strsplit(v, "\\."), `[[`, 3L)

output:

[1] "C"   "sad" "ED3"

answered Oct 23 '19 at 07:21

chinsoon12

score 2 · Answer 2 · answered Oct 23 '19 at 07:22

2

You can use unlist(strsplit(str,split = "."))[3] to get the third sub-string, where the original string is split by "." when you apply strsplit

answered Oct 23 '19 at 07:22

ThomasIsCoding

jay.sf · Answer 3 · 2019-10-23T07:29:40.483

2

Using regex in gsub.

v <- c("A.B.C.D", "apple.good.sad.sea", "X1.AN2.ED3.LK8", "A.B.C.D.E")
gsub("(.*?\\.){2}(.*?)(\\..*)", "\\2", v)
# [1] "C"   "sad" "ED3" "C"

edited Oct 23 '19 at 07:29

answered Oct 23 '19 at 07:24

jay.sf

score 2 · Answer 4 · answered Oct 23 '19 at 07:26

2

I'd use

sub("^([^.]*\\.){2}([^.]*)\\..*", "\\2", x)
# [1] "C"   "sad" "ED3"

answered Oct 23 '19 at 07:26

talat

4 Answers4