Question

Why the following code produces different output for me?

<% @comments.each do |comment| %>
  <%= comment.title %>
<% end %>

produces:

Title 1 title 2

but

<%= @comments.each { |comment| comment.title } %>

produces :

[#<Comment id: 1, commentable_id: 1, commentable_type: "Entry", title: "Title 1", body: "bla", subject: "", user_id: 1, parent_id: nil, lft: 1, rgt: 2, created_at: "2012-07-31 06:15:26", updated_at: "2012-07-31 06:15:26">, #<Comment id: 2, commentable_id: 1, commentable_type: "Entry", title: "tile 2", body: "one more comment", subject: "", user_id: 1, parent_id: nil, lft: 3, rgt: 4, created_at: "2012-08-01 06:58:57", updated_at: "2012-08-01 06:58:57">]

Answer 1

This is because <%= %> will print out the value returned by the block of code. In this case you have an enumerable @comments that you are calling each on. The method each will return the enumerable that is used, in this case @comments.

If you wanted to print out the collection of titles, you could use:

<%= @comments.map{ |comment| comment.title } %>

or more succinctly

<%= @comments.map(&:title) %>