FOR loop.... has many belongs to?

Hey,

I followed Ryan Bates tutorials here about implemting checkboxes with
has and belongs to many relationships.

http://railscasts.com/episodes/17-habtm-checkboxes

In case you dont have time to watch it, heres a quick summary--

<%= @product.categories.map(&:name).to_sentence %>

Hmmm thanks for the reply.. but nothing is showing up. no error
message though... is there a way to do this with a for loop?

I dont understand that peice of code.. im a rails noobie. could you
breifly explain? Thanks

This is saying that a product has many categories. The category name
will map to an array then the .to_sentence outputs each item as
1,2,3. nicely.

Thanks, but are you sure this works with has and belongs to many?

If you have a product instance you can do @product.categories correct
which returns an array of categories?