Question to regular expressions
Antje wrote:
Hi Gabor, it works! Thank you very much! But I still don't understand the difference between [0-9] and [:digit:]...
If all else fails, read the help, here ?regex. Both [0-9] and [[:digit:]] are character classes of digits, but the first contains only arabic numerals. In some locales the second may contain other numerals (e.g. Japanese has other characters representing digits): however I believe that in the current R implementations that no other numerals are included in any locale.
Ciao, Antje Gabor Grothendieck schrieb:
Try this:
folders <- c("folder1", "f2", "F234562", "12345678", "234567",
"912345", "333")
grep("^[0-9]{6}$", folders, value = TRUE)
[1] "234567" "912345" On Tue, Dec 2, 2008 at 10:32 AM, Antje <niederlein-rstat at yahoo.de> wrote:
Hi there,
I know, this question is not directly an R-help question but probably
someone can give me a hint how to deal with the following problem.
I have a vector with file/folder names and want to filter for all
entries
which have 6 numbers in a row and nothing else.
folders <- c("folder1", "f2", "F234562", "12345678", "234567", "912345",
"333")
I'd like to get only "234567" and "912345".
Can anybody help me creating a regex for this???
For example this regex:
regexpr("[^:digit:$]{6}", folders)
would match "F234562", "12345678", "234567", "912345"
Antje
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