title: Typescript: What is type URL?
body: <p>I want to make sure that an interface member of type string is a formally valid URL. I could declare a member as URL but I cannot assign it a string that is a valid URL.</p>
  
  <pre><code>interface test {
      myurl: URL;
  }
  
  var a : test;
  a.myurl = "http://www.google.ch"
  </code></pre>
  
  <p>When compiling I get: </p>
  
  <blockquote>
    <p>Type 'string' is not assignable to type 'URL'.</p>
  </blockquote>
  
  <p>Do I have to use decorators for my task (<a href="https://www.typescriptlang.org/docs/handbook/decorators.html" rel="noreferrer">https://www.typescriptlang.org/docs/handbook/decorators.html</a>)? </p>
  
  <p>And what is URL good for?</p>
  
  <p>I am using typescript 1.8.10</p>