junk$y extracts the element named "y" because it found an exact match for the name.
junk$yu extracts nothing because it does not find an exact match and finds multiple partial matches. junk$yuc or junk$yur would work because it finds no exact match and then exactly one partial match. On Tue, Jan 24, 2023, 17:04 Rolf Turner <r.tur...@auckland.ac.nz> wrote: > > Has something changed, but I missed it? > > My recollection is that $ extraction used partial matching. > > E.g. if one did > > junk <- list(yuck=1,yurk=2,y=3) > junk$y > > then one would get 1 as the result; probably *not* the desired result. > See fortunes::fortune("toad"). > > To get the desired result, one would need to use junk[["y"]]. > > Likewise junk$yu would give 1; to get the value of "yurk", one would > need to use junk$yur or junk$yurk or (better?) junk[["yurk"]]. > > However, either my recollection is wrong, or something has changed. > When I do junk$y I get 3 (the "right" answer; the same as junk[["y"]]). > When I do junk$yu I get NULL (just as if I'd done junk[["yu"]]). > > So: has something changed, or am I miss-remembering, or am I completely > confused about the whole issue? > > Thanks for any enlightenment. > > cheers, > > Rolf Turner > > -- > Honorary Research Fellow > Department of Statistics > University of Auckland > Phone: +64-9-373-7599 ext. 88276 > > ______________________________________________ > 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.