title: In Ruby, why do you need to initialize child class variables?
body: <p>I have a class Foo, I create a child case Bar. 
  Why must I initialize the @foo_count in the child-class if it's already been initialized in the parent class?</p>
  
  <p>Please advise?</p>
  
  <pre><code>class Foo
    @foo_count = 0  
  end
  
  class Bar &lt; Foo
    @foo_count = 100
  end
  </code></pre>