title: ruby array checking for nil array
body: <p>I have ruby array and it is <code>nil</code> but when I check using <code>nil?</code> and <code>blank?</code> it returns <code>false</code></p>
  
  <pre><code>@a = [""]
  
  @a.nil?
  =&gt; false
  
  @a.empty?
  =&gt; false
  </code></pre>
  
  <p>How do I check for the nil condition that return true?</p>