denisdefreyne

"snow" + "plow" == "snowplow"
# => true

("snow" + "plow").equal?("snowplow")
# => false

denisdefreyne

"/usr/bin/ruby" == path     # => true
"/usr/bin/python" == path   # => false

denisdefreyne

path = Path.new("usr", "bin", "ruby")

path == path                # => true
path == "/usr/bin/ruby"     # => true
path == "/usr/bin/python"   # => false

path == 12.3   # => false

denisdefreyne

class Path
  # …
  def ==(other)
    other.respond_to?(:to_str) &&
      to_str == other.to_str
  end

  def to_str
    string
  end

denisdefreyne

path = Path.new("usr", "bin", "ruby")
path.string == "/usr/bin/ruby"   # => true
path == "/usr/bin/ruby"          # => false :(

denisdefreyne

class Path
  # …
  def ==(other)
    self.class == other.class &&
      @components == other.components
  end
end

denisdefreyne

path = Path.new("usr", "bin", "ruby")
path.string   # => "/usr/bin/ruby"

denisdefreyne

class Path
  attr_reader :components

  def initialize(*components)
    @components = components
  end

  def string
    "/" + @components.join("/")
  end

denisdefreyne

float_two = 2.0
integer_two = 2

denisdefreyne

denis       = Employee.new(570, "Denis Defreyne")
also_denis  = Employee.new(570, "Denis")
denis_v     = Employee.new(992, "Denis Villeneuve")
new_denis_1 = Employee.new(nil, "Denis 1")
new_denis_2 = Employee.new(nil, "Denis 2")

denis == denis               # => true
denis == also_denis          # => true
denis == "cucumber"          # => false
denis == denis_v             # => false