gistfile1.rb

pry(main)> show-doc Array#sort!

From: array.c (C Method):
Number of lines: 9
Owner: Array
Visibility: public
Signature: sort!()

Sorts self. Comparisons for
the sort will be done using the <=> operator or using
an optional code block. The block implements a comparison between
a and b, returning -1, 0, or +1. See also
Enumerable#sort_by.

   a = [ "d", "a", "e", "c", "b" ]
   a.sort                    #=> ["a", "b", "c", "d", "e"]
   a.sort {|x,y| y <=> x }   #=> ["e", "d", "c", "b", "a"]