

   LLeennggtthh ooff aa VVeeccttoorr oorr LLiisstt

        length(x)
        length(x) <- n

   DDeessccrriippttiioonn::

        If `x' is a vector or list `length' returns the length
        of `x'.  Otherwise, `length' returns `NA'.

        The second form above can be used to reset the length
        of a vector.  If a vector is shortened, extra values
        are discarded and when a vector is lengthened, it is
        padded out to its new length with `NA's.

