Is it fine to keep an empty string as array key?
<p>I want to know is it fine if we keep an empty string as array key, like this</p>

<pre><code>$test = array (
  '' =&gt; 'Select',
  1 =&gt; 'Internal',
  2 =&gt; 'External'
);
</code></pre>

<p>Any suggestions would be appreciated.</p>