Method practice.

method.rb

# dynamic dispatch
puts '##### dynamic dispatch'
class Student
  def initialize
    @name = 'Joe'
  end

  def original
    "#{@name}'s original score: { math: 60, eng: 56 }"
  end

end

s = Student.new
puts s.send(:original) #=> { :math=>60, :eng=>56 }

# dynamically define method
puts '##### dynamically define method'
class Student
  define_method :cheating do
    "#{@name}'s cheating score: { math: 98, eng: 96 }"
  end

end

puts s.cheating #=> { :math=>98, :eng=>96 }

# ghost method
puts '##### ghost method'
class Student
  def method_missing(method_name)
    if method_name =~ /^report$/
      "#{method_name}: not want to study!"
    else
      super
    end
  end
end

puts s.report
begin
  puts s.report_not_exists
rescue Exception => ex
  puts ex
end

# dynamic proxy
puts '##### dynamic proxy'
class Student
  def method_missing(method_name)
    if method_name =~ /^study_hard$/
      cheating
    else
      super
    end
  end
end

puts s.study_hard