class.erb

<h1>Listing Classes</h1>
<table>
  <thead>
    <tr>
      <th>Name</th>
      <th colspan=3></th>
    </tr>
  </thead>
  <tbody>
    <% @klasses.each do |klass| %>
      <tr>
        <td><%= klass.name %></td>
        <td><%= link_to 'Show', klass %></td>
        <td><%= link_to 'Edit', edit_klass_path(klass) %></td>
        <td><%= link_to 'Destroy', klass, method: :delete, data: { confirm: 'Are you sure?' } %></td>
      </tr>
    <% end %>
  </tbody>
</table>
<%= link_to 'New Klass', new_klass_path %>

class.haml

%h1 Listing Classes
%table
  %thead
    %tr
      %th Name
      %th{ colspan: 3 }
  %tbody
    - @klasses.each do |klass|
      %tr
        %td= klass.name
        %td= link_to 'Show', klass
        %td= link_to 'Edit', edit_klass_path(klass)
        %td= link_to 'Destroy', klass, method: :delete, data: { confirm: 'Are you sure?' }
= link_to 'New Class', new_klass_path