除非另加价值

Question

In a rails loop with many values, what's the best method of doing something like:

<% @results.each do |r| %>
<%= r.title, unless r.title.blank? puts 'N/A' %>
<%= r.year, unless r.year.blank? puts 'N/A' %>
<%= r.description, unless r.description.blank? puts 'N/A' %>
<% end %>

Answer 1

<%= r.title.presence || 'N/A' %>

等等...

Answer 2

I would probably do something like

r.title.presence || 'N/A'

You should not use puts here. puts is for writing to stdout .

Answer 3

Try with:

<% @results.each do |r| %>
  <%= r.title.presence || 'N/A' %>
  <%= r.year.presence || 'N/A' %>
  <%= r.description.presence || 'N/A' %>
<% end %>

You may also want to have a look to the Draper gem .