Reverse the order of items in {object}. {object} can be a List, a Blob or a String. For a List and a Blob the items are reversed in-place and {object} is returned. For a String a new String is returned. Returns zero if {object} is not a List, Blob or a String. If you want a List or Blob to remain unmodified make a copy first:

:let revlist = reverse(copy(mylist))

Can also be used as a method:

mylist->reverse()