def last:

docs/content/manual/manual.yml

@@ -2365,7 +2365,7 @@ sections:
           so are only useful for genuine Boolean operations, rather
           than the common Perl/Python/Ruby idiom of
           "value_that_may_be_null or default". If you want to use this
-          form of "or", picking between two values rather than
+          form of "or", choosing between two values rather than
           evaluating a condition, see the `//` operator below.
 
         examples:

src/builtin.jq

@@ -168,7 +168,7 @@ def nth($n; g):
   if $n < 0 then error("nth doesn't support negative indices")
   else label $out | foreach g as $item ($n + 1; . - 1; if . <= 0 then $item, break $out else empty end) end;
 def first: .[0];
-def last: .[-1];
+def last: .[length-1];
 def nth($n): .[$n];
 def combinations:
     if length == 0 then [] else

tests/jq.test

@@ -1051,8 +1051,12 @@ pick(first|first)
 [[10,20],30]
 [[10]]
 
-# negative indices in path expressions (since last/1 is .[-1])
-try pick(last) catch .
+pick(last)
+[1,2]
+[null,2]
+
+# negative indices in path expressions are disallowed
+try pick(.[-1]) catch .
 [1,2]
 "Out of bounds negative array index"