Tena koe Yu ?is.null
HTH ... Peter Alspach > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of Yuan Jian > Sent: Monday, 26 July 2010 5:05 p.m. > To: r-help@r-project.org > Subject: [R] NULL > > hi, > I have a simple problem. > > how can I test whether a variable is NULL? > > a = NULL > if (a == NULL){ > ... > } > it seems not work > > thanks > > YU > > > > > > > [[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. ______________________________________________ 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.
