How to pass a custom comparator to “sort”?

Question

Class A has the following comparator:

class A
  attr_accessor x

  def my_comparator(a)
    x**2 <=> (a.x)**2
  end
end

Answer 1

Both of these should work:

items.sort_by! { |a| (a.x)**2 }
items.sort! { |a1,a2| a1.my_comparator(a2) }