title: AS3 - nulling elements within a Vector structure
body: <p>I'm using a Vector structure in ActionScript 3 to store references to a custom class. My Vector is fixed length for performance reasons, and also because it needs to map 1:1 to another data structure.</p>
  
  <p>I'm trying to figure out how I "remove" an element from this fixed list. I don't want the length of the Vector to change, I just want the value of that element to be "null". Or more specifically, when I test for the truth of that element (eg: if (myVector[index]) { // do something... }), I want that test to fail for that element, since it's "empty".</p>
  
  <p>So naturally, I've tried:</p>
  
  <pre><code>myVector[index] = null;
  </code></pre>
  
  <p>but that throws a TypeError, as does</p>
  
  <pre><code>myVector[index] = Vector.&lt;MyClass&gt;([]);
  </code></pre>
  
  <p>So what's the process for "emptying" an element of a Vector?</p>