title: Initializing a TypeScript array interface
body: <p>Why is this illegal in TypeScript?</p>
  
  <pre><code>interface numarr {
      [i : number] : number;
  }
  
  var p : numarr = [3,6,8];
  </code></pre>
  
  <p>The compiler says "Cannot convert 'number[]' to 'numarr'."</p>
  
  <p>I'm afraid I've misunderstood something quite basic here. I thought the point of the above interface was to describe an array of numbers indexed by numbers, which is exactly what [3,6,8] is.</p>