Custom + Method in Ruby String

Question

I am trying to modify the Ruby String class, specifically the + method. I want it to return a specific string, such that

 "a" + "b" => "custom_result"

Here's what I have:

class String

  def +(a)
    "custom_result"
  end

end

When I try to require this file in irb, "custom_result" is in my prompt, and I can't execute anything. Any ideas?

Answer 1

Well, IRb uses the String class both to print the results and to parse what you type into it. If you mess with that, IRb breaks, that's not really surprising.