title: Get hash key and convert into string ruby
body: <p>Example Hash</p>
  
  <pre><code>hash = {:key =&gt; ["val1", "val2]}
  </code></pre>
  
  <p>When I did this on rails 3.0.7, it was fine.</p>
  
  <pre><code>&gt; hash.keys.to_s
   =&gt; "key"
  &gt; hash[hash.keys.to_s]
   =&gt; ["val1", "val2"]
  </code></pre>
  
  <p>But if I do this with rails 3.1.3, it isn't.</p>
  
  <pre><code>&gt; hash.keys.to_s
   =&gt; [\"key\"]
  &gt; hash[hash.keys.to_s]
   =&gt; nil
  </code></pre>
  
  <p><strong>Is this was because of the Rails version changed?</strong> and <strong>Is there any other way to turn hash key into a string that works with both version (or with rails 2 too)?</strong></p>