CODEWITHSUNDEEP
rubymethods
Napoleon
Napoleon

Reputation: 1102

How do I get all custom methods in a class?

module Test
  class A
    def hi
      p 'hi'
    end

    def bye
      p 'bye'
    end

    puts methods.sort
    p '---------'
    puts methods.sort - Object.methods
  end
end

The second puts does not print anything, the first one does not print 'hi' and 'bye'. Why?

Upvotes: 1

Views: 686

Answers (2)

Arup Rakshit
Arup Rakshit

Reputation: 118271

I think you confused yourself between method and instance_methods:

module Test
  class A
    def hi
      p 'hi'
    end

    def bye
      p 'bye'
    end

    puts instance_methods.sort
    p '---------'
    puts instance_methods.sort - Object.instance_methods
  end
end

Output:

[:!, :!=, :!~, :<=>, :==, :===, :=~, :__id__, :__send__, :bye, :class, :clone, :define_singleton_method, :display, :dup, :enum_for, :eql?, :equal?, :extend, :freeze, :frozen?, :hash, :hi, :inspect, :instance_eval, :instance_exec, :instance_of?, :instance_variable_defined?, :instance_variable_get, :instance_variable_set, :instance_variables, :is_a?, :kind_of?, :method, :methods, :nil?, :object_id, :private_methods, :protected_methods, :public_method, :public_methods, :public_send, :remove_instance_variable, :respond_to?, :send, :singleton_class, :singleton_methods, :taint, :tainted?, :tap, :to_enum, :to_s, :trust, :untaint, :untrust, :untrusted?]
"---------"
[:bye, :hi]

Upvotes: 2

Sergio Tulentsev
Sergio Tulentsev

Reputation: 230336

Because both lines are executed in scope of A class itself, while hi and bye are instance methods of that class. Try this: 

module Test
  class A
    def hi
      p 'hi'
    end

    def bye
      p 'bye'
    end

    puts instance_methods(false)
  end
end

# >> hi
# >> bye

When you pass false to instance_methods, you instruct it to not include methods of super classes.

Upvotes: 6

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