What's the difference between <% code %> and <%= code %> in Rails erb?

Question

There seems to be a difference between the two, Though I can\'t tell what exactly.

<% code %>

And

<%= code %>
<         


        

Answer 1

<% %> will evaluate the ruby code contained

<%= %> will evaluate and render the code contained

So a template containing:

Hello <% user.name %> how are you?

...would output:

Hello  how are you

...whilst...

Hello <%= user.name %> how are you?

...would output:

Hello fred how are you

<% %> is commonly used for iterators

  <% @users.each do |user| %>
    
<%= user.name %>
  <% end %>