Question

Here is my ruby code

class Demo
  attr_accessor :lines

  def initialize(lines)
    self.lines = lines
  end
end

In the above code I could have used

    @lines = lines

Mostly I see people using @ in initialize method. Is there a preferred way of doing among these two and why?

Answer 1

When you use @lines, you are accessing the instance variable itself. self.lines actually goes through the lines method of the class; likewise, self.lines = x goes through the lines= method. So use @ when you want to access the variable directly, and self. when you want to access via the method.

To directly answer your question, normally you want to set the instance variables directly in your initialize method, but it depends on your use-case.