Document that lengths() preserve dimensions (PR#18858).

git-svn-id: https://svn.r-project.org/R/trunk@88894 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: kalibera

src/library/base/man/lengths.Rd

@@ -1,6 +1,6 @@
 % File src/library/base/man/lengths.Rd
 % Part of the R package, https://www.R-project.org
-% Copyright 1995-2023 R Core Team
+% Copyright 1995-2025 R Core Team
 % Distributed under GPL 2 or later
 
 \name{lengths}
@@ -41,7 +41,7 @@ lengths(x, use.names = TRUE)
   except when any element has a length of more than
   \eqn{2^{31}-1}{2^31 - 1} elements, when it returns a double vector.
   When \code{use.names} is true, the names are taken from the names on
-  \code{x}, if any.
+  \code{x}, if any. The result has the same dimensions as \code{x}.
 }
 \seealso{
   \code{\link{length}} for getting the length of any \R object.