The Ruby %r{ } expression

Question

In a model there is a field

validates :image_file_name, :format => { :with => %r{\\.(gif|jpg|jpeg|png)$}i

It looks pretty odd for me.

Answer 1

It mean that image_file_name must end ($) with dot and one of gif, jpg, jpeg or png.

Yes %r{} mean exactly the same as // but in %r{} you don't need to escape /.