• Here, we'll improve the detail of our error messages.
• We'll learn a bit about how the flash works.
• When objects don't validate, Rails automatically provides errors that can be accessed with the .errors method.

###app/controllers/contacts_controller.rb

...
def create
  @contact = Contact.new(contact_params)
  if @contact.save
     flash[:success] = "Message sent."
     redirect_to new_contact_path
  else
     flash[:error] = @contact.errors.full_messages.join(", ")
     redirect_to new_contact_path
  end
end
...

###app/views/contacts/new.html.erb

...
<%= flash[:error] %>
...

###Terminal

git status
git add .
git commit -m "Improved error messages"
git push origin contact_form