Append an object to a list in R?
- by Nick
If I have some R list mylist, you can append an item obj to it like so:
mylist[[length(mylist)+1]] <- obj
But surely there is some more compact way. When I was new at R, I tried writing append() like so:
append <- function(lst, obj) {
lst[[length(list)+1]] <- obj
return(lst)
}
but of course that doesn't work due to R's call-by-name semantics (lst is effectively copied upon call, so changes to lst are not visible outside the scope of append(). I know you can do environment hacking in an R function to reach outside the scope of your function and mutate the calling environment, but that seems like a large hammer to write a simple append function.
Can anyone suggest a more beautiful way of doing this? Bonus points if it works for both vectors and lists.
