Please explain the rationale behind this simple javascript interview question
<p>Consider this program:</p>

<pre><code>(function(x){
  delete x;
  return x;
})(1);
</code></pre>

<p>What is the output? </p>

<p>It happens to be <code>1</code> and not <code>undefined</code> as I expected. I thought <code>x</code> purely is in the scope of function and deleting it inside the function should have made it inaccessible to outside it. </p>

<p>Can someone throw a little light on this? </p>
