* array.c: [DOC] Add note about negative indices in Array overview

By @ckaenzig [Fixes GH-427] https://github.com/ruby/ruby/pull/427


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43570 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Fri Nov  8 02:14:37 2013  Zachary Scott  <e@zzak.io>
+
+	* array.c: [DOC] Add note about negative indices in Array overview
+	  By @ckaenzig [Fixes GH-427] https://github.com/ruby/ruby/pull/427
+
 Fri Nov  8 02:09:12 2013  Zachary Scott  <e@zzak.io>
 
 	* lib/csv.rb: [DOC] Fix typo in CSV.parse_line by @funky-bibimbap

array.c

@@ -5404,7 +5404,8 @@ rb_ary_drop_while(VALUE ary)
  *
  *  Elements in an array can be retrieved using the Array#[] method.  It can
  *  take a single integer argument (a numeric index), a pair of arguments
- *  (start and length) or a range.
+ *  (start and length) or a range. Negative indices start counting from the end,
+ *  with -1 being the last element.
  *
  *     arr = [1, 2, 3, 4, 5, 6]
  *     arr[2]    #=> 3
@@ -5412,6 +5413,7 @@ rb_ary_drop_while(VALUE ary)
  *     arr[-3]   #=> 4
  *     arr[2, 3] #=> [3, 4, 5]
  *     arr[1..4] #=> [2, 3, 4, 5]
+ *     arr[1..-3] #=> [2, 3, 4]
  *
  *  Another way to access a particular array element is by using the #at method
  *