title: Is this a bug with PHP array accessing?
body: <p>I ran into this bug where an element of an array, if its index is the string "0", is inaccessible. </p>
  
  <p>It's not a bug with unserialize, either, as this occurred in my code without invoking it.</p>
  
  <pre><code>$arr = unserialize('a:1:{s:1:"0";i:5;}');
  var_dump($arr["0"]); //should be 5, but is NULL
  var_dump($arr[0]);   //maybe this would work?  no. NULL
  </code></pre>
  
  <p>Am I doing something wrong here?  How do I access this element of the array?</p>