There is no function columns() in base R. Is 'date' an object that contains column names or indices? Or do you mean that it is a string that appears in the column names you wish to loop over?
A small reprex should be easy to provide to show us explicitly what you want. Please do so -- unless, of course, someone with greater insight than I provides you a satisfactory answer. Cheers, Bert On Tue, Nov 15, 2022 at 8:19 AM Kai Yang via R-help <r-help@r-project.org> wrote: > Hi Team, > I can write a for loop like this: > for (i in columns(df)){ > ...... > } > > But it will working on all column in dataframe df. If I want to work on > some of specific fields (say: the fields' name content 'date'), how should > I modify the for loop? I changed the code below, but it doesn't work. > for (i in columns(df) %in% 'date' ){ > ..... > } > > > Thank you, > Kai > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.