问题
In urls and rails routing, what is the difference between using a slash character vs a pound sign (hash sign) character?
These work
get "/static_pages/about"
get 'about', to: 'static_pages#about', as: :about
These don't
get "/static_pages#about"
get 'about', to: 'static_pages/about', as: :about
get 'about', to: '/static_pages#about', as: :about
What code controls this behavior, and what is the deeper reason behind it?
ANSWER:
(The two people answered it very well, and I had trouble choosing which one to mark as the accepted answer. I wish to state my understanding of the answer in a different way that might help people.)
Once you use the / symbol, the string gets recognized as a url string appended to the base url. So a '#' character will be interpreted as part of the url, and urls don't like to take '#' characters.
In the case of not using a / character, the first word is recognized somehow as a controller name, which you follow up with a '#' and an action name.
回答1:
The # in to: 'static_pages#about' means about action of static_pages_controller. The syntax is controller#action.
When you define get "/static_pages#about", static_pages#about becomes the controller for the route i.e. the # is only a character literal and #about does not mean about action. You should get a missing :controller error if static_pages#about controller does not exist.
The following route definition gives you /about path which maps to static_pages/about controller's about action, where static_pages could either be a namespace or a scope.
get 'about', to: 'static_pages/about', as: :about
The following route is invalid and should throw an error due to the leading slash / in to option.
get 'about', to: '/static_pages#about', as: :about
回答2:
In ruby, the hash symbol generally precedes the name of a instance method of a class. See the left sidebar of the page of the Array class documentation (http://www.ruby-doc.org/core-2.1.0/Array.html).
get "/static_pages#about" doesn't work because #about is not part of the url.
get 'about', to: 'static_pages/about', as: :about doesn't work because /about doesn't indicate which controller method should be called.
get 'about', to: '/static_pages#about', as: :about doesn't work because of the preceding slash before static_pages.
来源：https://stackoverflow.com/questions/21372675/rails-routes-slash-character-vs-hash-character