Comparable

Syntax#

include Comparable
implement the space-ship operator (<=>)

Parameters#

Parameter	Details
other	The instance to be compared to `self`
## Remarks#
`x <=> y` should return a negative number if `x < y`, zero if `x == y` and a positive number if `x > y`.
## Rectangle comparable by area
`Comparable` is one of the most popular modules in Ruby. Its purpose is to provide with convenience comparison methods.

To use it, you have to include Comparable and define the space-ship operator (<=>):

class Rectangle
  include Comparable

  def initialize(a, b)
    @a = a
    @b = b
  end

  def area
    @a * @b
  end

  def <=>(other)
    area <=> other.area
  end
end

r1 = Rectangle.new(1, 1)
r2 = Rectangle.new(2, 2)
r3 = Rectangle.new(3, 3)

r2 >= r1 # => true
r2.between? r1, r3 # => true
r3.between? r1, r2 # => false