How to access the last value in a vector?

Suppose I have a vector that is nested in a dataframe with one or two levels. Is there a quick and dirty way to access the last value, without using the length() function? Something ala PERL's $# special var? So I would like something like: dat$vec1$vec2[$#] instead of: dat$vec1$vec2[length(dat$vec1$vec2)]

[vvwashika]

最後の要素の取り出し方