• We'll rewrite the flash display inside an Each loop.
• The Each loop, when used with flash, allows us to use two temporary variables - we'll call them 'type' and 'msg', since we can name them whatever we want.
• We'll output a div using the Rails content_tag function inside the loop.
• By doing all of this, we have a dynamically generated flash message with dynamically generated CSS classes applied.
• Dynamic is a buzzword used to say the content was computed instead of hard-coded by hand.

####app/views/layouts/application.html.erb

...
<% flash.each do |type, msg| %>
  <%= content_tag :div, msg, class: "alert alert-#{type}" %>
<% end %>
...

###app/controllers/contacts_controller.rb

...
flash[:danger] = @contact.errors.full_messages.join(", ")
...

###Terminal

git status
git add .
git commit -m "Improved flash style"
git push origin contact_form