I am new to R, and I have been running into the following situation when I mistype a variable name in some code:
> list1 <- list( a=1, b=2 ) > list2 <- list( a=1 ) > list2$b <- list1$c > list2 $a [1] 1 I would think at the point where I am trying to reference a field called "c" -- that does not exist -- in list1, there would be an error flagged. Instead, list1$c returns value NULL, and the assignment "list2$b <- NULL" does not return any error, but also does not create a field called "b" in list2. Is there a way to have R flag the reference to field "c" in list1 as an error? Thanks, Harry ______________________________________________ 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.
