title: When do Ruby instance variables get set?
body: <pre><code>class Hello
  @hello = "hello"
      def display
          puts @hello
      end
  end
  
  h = Hello.new
  h.display
  </code></pre>
  
  <p>I created the class above. It doesn't print anything out. I thought the instance variable @hello was set during the class declaration. But when I call the display method the output is 'nil'. What's the correct way to do this?</p>