title: At symbol (@) in link_to argument in Rails
body: <p>everybody. Forgive any mistakes in my English since it's my second language. Also only my second question here.</p>
  <p>I'm learning Ruby on Rails and I have a very basic question, but sadly wasn't able to find a specific answer anywhere.</p>
  <p>So, all I did is a simple scaffold (rails g scaffold book title author status:integer), nothing more, and I'm studying everything it does. That's all.</p>
  <p>The thing is I don't understand why in the index view the &quot;link_to&quot; helper uses &quot;book&quot; as argument instead of &quot;@books&quot; for both Edit and Destroy links.</p>
  <p><a href="https://i.stack.imgur.com/4ebM1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4ebM1.png" alt="enter image description here" /></a></p>
  <p>Since in the show view the same &quot;link_to&quot; uses @book for Edit.</p>
  <p><a href="https://i.stack.imgur.com/4ITK9.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4ITK9.png" alt="enter image description here" /></a></p>
  <p>At first, I thought they could be interchangeable, but they aren't, since when I change the &quot;@&quot;, Rails throws an error.
  I'm clearly missing something basic here.</p>
  <p>Where does this difference in both views come from?</p>
  <p>Thank you all.</p>