Test for the condition you are looking for. If the grep does not match, it returns a vector of length zero
> a='hello world' > if (length(grep('hellow',a)) != 0) { + print("wow") + } else { + print("wow2") + } [1] "wow2" > On Thu, Mar 11, 2010 at 6:59 PM, Dan Joo <d...@agraquest.com> wrote: > I am new to R, so I beg your indulgence. > > a='hello world' > > if (grep('hellow',a)) { > print("wow") > } else { > print("wow2") > } > Error in if (grep("hellow", a)) { : argument is of length zero > > What is the proper syntax to ensure that "wow2" gets printed? > > Thank you for your help! > > Dan > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.