title: ruby Initializing instance variable outside method
body: <p>As an experiment, I wrote some code that looks like</p>
  
  <pre><code>class MyClass
  
      @var = 100
  
      def hello
        p "hello"
      end
  
  end
  </code></pre>
  
  <p>I know that if I do <code>MyClass.new</code> that <code>@var</code> is not defined on that object, rather I think this would define <code>@var</code> on the class <code>MyClass</code>.</p>
  
  <p>Is there a practical usage to this?</p>