How to make the class constructor private in Ruby?

Question

class A
private
  def initialize
    puts \"wtf?\"
  end
end

A.new #still works and calls initialize

and

class A
private
  def sel         


        

Answer 1

The second chunk of code you tried is almost right. The problem is private is operating in the context of instance methods instead of class methods.

To get private or private :new to work, you just need to force it to be in the context of class methods like this:

class A
  class << self
    private :new
  end
end

Or, if you truly want to redefine new and call super

class A
  class << self
    private
    def new(*args)
      super(*args)
      # additional code here
    end
  end
end

Class-level factory methods can access the private new just fine, but trying to instantiate directly using new will fail because new is private.