title: Ruby hash access value from string array
body: <p>I have an hash like below:</p>
  
  <pre><code>hash = {"a": [{"c": "d", "e": "f"}] }
  </code></pre>
  
  <p>Normally we can access it like <code>hash["a"][0]["c"]</code>.</p>
  
  <p>But, I have a string like:</p>
  
  <pre><code>string = "a[0]['c']"
  </code></pre>
  
  <p>(This can change depending upon user input)</p>
  
  <p>Is there any easy way to access hash using above string values?</p>