title: check if item can be converted to string?
body: <p>I am writing a debug method.</p>
  <p>What I have is</p>
  <pre><code>if(is_xxx($item)){
   //echo output info for type
  }
  </code></pre>
  <p>what I want to do at the end is</p>
  <pre><code>if(can_be_string($item))
  echo $item;
  </code></pre>
  <p>Is there a <code>can_be_string</code> type function?</p>