[R] Check if string has all alphabets or numbers

[jim holtman]

Here is the way you can use grepl to get the various combinations:

> mywords<- c("harry","met","sally","subway10","1800Movies","12345",
+ "not correct 123", "")
>
> numbers <- grepl("^[[:digit:]]+$", mywords)
> letters <- grepl("^[[:alpha:]]+$", mywords)
> both <- grepl("^[[:digit:][:alpha:]]+$", mywords)
>
> mywords[letters]
[1] "harry" "met"   "sally"
> mywords[numbers]
[1] "12345"
> mywords[xor((letters | numbers), both)] # letters & numbers mixed
[1] "subway10"   "1800Movies"
>
>


On Mon, Nov 23, 2009 at 9:17 AM, hadley wickham <h.wickham at gmail.com> wrote:
>>> mywords<- c("harry","met","sally","subway10","1800Movies","12345", "not correct 123")
>>> all.letters <- grep("^[[:alpha:]]*$", mywords)
>>> all.numbers <- grep("^[[:digit:]]*$", mywords)  # numbers
>>> mixed <- grep("^[[:digit:][:alpha:]]*$", mywords)
>
> mywords<- c("harry","met","sally","subway10","1800Movies","12345",
> "not correct 123", "")
> mywords[grepl("^[[:digit:][:alpha:]]*$", mywords)]
>
> So maybe you should use
>
> mywords[grepl("^[[:digit:][:alpha:]]+$", mywords)]
>
>
> And grepl is highly recommended over grep.
>
> Hadley
>
> --
> http://had.co.nz/
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

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