reverse LIST
In list context, this function returns a list value consisting
of the elements of LIST
in the opposite order. This is fairly
efficient because it just swaps the pointers around. The function can
be used to create descending sequences:
for (reverse 1 .. 10) { ... }
Because of the way hashes flatten into lists when passed to (non-hash-aware) functions, reverse can also be used to invert a hash, presuming the values are unique:
%barfoo = reverse %foobar;
In scalar context, the function concatenates all the elements of LIST
together and then returns the reverse of that, character by character.
A small hint: reversing a list sorted earlier by a user-defined function can sometimes be achieved more easily by simply sorting in the opposite direction in the first place.