Where to place private methods in Ruby?

Question

Most of the blogs or tutorials or books have private methods at the bottom of any class/module. Is this the best practice?

I find having private methods as and when nece

Answer 1

The best practice in my point of view is to go sequentially and declare your methods without keeping private in point of view.

At the end, you can make make any method private by just adding: private :xmethod

Example:

class Example
 def xmethod
 end

 def ymethod
 end

 def zmethod 
 end

 private :xmethod, :zmethod

end

Does this justify your question?

Answer 2

I don't like having to specify public or private for each method. Putting all private methods at the bottom lets me have a single instance of "private" per file. I guess it's a matter of taste.

Answer 3

Dennis had the perfect answer, that is, when using ruby >=2.1, just prefix the def with private (or protected,public)

But I believe that it's now also possible to use private as a block as in:

private begin
   def foo
   end
   def bar
   end
end

def zip
end

Answer 4

I'm coming from java background and I hate to have to scroll to see method type. I think it's insane that one cannot specify method visibility per method without ugliness. So I ended up putting a comment #private before each suck method and then declaring private :....

Answer 5

As others have already pointed out the convention is to put private methods at the bottom, under one private class. However, you should probably also know that many programers use a double indented (4 spaces instead of 2) method for this. The reason is that often times you won't see "private" in your text editor and assume they could be public. See below for an illustration:

class FooBar

  def some_public_method
  end

  def another_public_method
  end

private

    def some_private_method
    end

    def another_private method
    end

end

This method should prevent you from having to scroll up and down and will make other programmers more comfortable in your code.

Answer 6

I generally order my methods as follows:

1. Constructor
2. Other public methods, in alphabetical order
3. private, written only once
4. Private methods, in alphabetical order

I use “go to definition” features in my editor so that this doesn’t involve much scrolling, and in any case, if the class is big enough that scrolling becomes problematic, it probably should be broken up into several classes.