Matching a character in a string

Hello.

Sorry for this very basic question but I didn't find (of didn't understand)
the answer either in the help or in the online guide.

I have a string, let's say "hello". I want to know if there is some
character in it, let's say an 'o'.

I tried

  

charmatch("o", strstplit("hello",""))
    

but it gives NA (why??)

Thinking it may be a type problem, I tried

  

charmatch("o",as.character(strsplit("hello","")))
    

but it gives NA too (why???)

So how can I know if a given string contains a given char?

Thanks!

  

try:

grep("o", "hello")

if the output is 1, there is a match. Note that the command is 
vectorized so:

grep("o", c("hello","pizza", "spam", "ogle"))

also works, picking out items 1 and 4 as containing an "o". The first 
argument to grep is a regular expression, and this can be very powerful. 
For example, which words start with a "p":

grep("^p", c("hello","pizza", "spam", "ogle"))

Check out more stuff on regular expressions on the internet. They are 
very powerful, but take some time to learn.

cheers,
Paul

Drs. Paul Hiemstra
Department of Physical Geography
Faculty of Geosciences
University of Utrecht
Heidelberglaan 2
P.O. Box 80.115
3508 TC Utrecht
Phone:  +3130 274 3113 Mon-Tue
Phone:  +3130 253 5773 Wed-Fri
http://intamap.geo.uu.nl/~paul

The output from strsplit("hello","") is not suitable as input for the second
argument for charmatch.

compare with:

 charmatch("o",strsplit("hello","")[[1]])

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See also ?unlist  (you can unlist(strsplit(...)) for the same effect

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grep("o", "hello")

Thanks, I hadn't noticed R has grep included!

Fabrice DELENTE