title: Angular2 TypeScript interface array not working
body: <p>I am writing an Angular2 application. I want to display messages using an interface and an array containing all the messages. Here is the interesting part of my TypeScript component:</p>
  
  <pre><code>export class ChatComponent
  {
    messages: message[];
    constructor()
    {
      this.messages.push({from: 'me', time: new Date().getTime(), type: 'text', value: 'Hallo Welt!', sent: new Date().getTime(), delivered: 0, read: 0});
    }
  }
  
  interface message
  {
    from: string;
    time: number;
    type: string;
    value: string;
    sent: number;
    delivered: number;
    read: number;
  }
  </code></pre>
  
  <p>As you can see from TypeScript side of things everything looks alright (I guess). Displaying stuff in the template worked fine, in this case I am using the following:</p>
  
  <pre><code>&lt;div class = "message" *ngFor = "let message of messages"&gt;
    &lt;div&gt;{{message.value}}&lt;/div&gt;
    &lt;div&gt;{{message.time}}&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>When just using an array and filling it with objects this setup is working fine. But as soon as I use the interface <code>message</code> and the array I get</p>
  
  <pre><code>EXCEPTION: Error in :0:0 caused by: this.messages is undefined
  </code></pre>
  
  <p>I feel like it's some stupid mistake or misunderstanding, but couldn't find anything useful. Why should <code>this.messages</code> be undefined?</p>