How to initialize a field by calling a method
<p>The following class refuses to compile: </p>

<pre><code>class InitTest { // Class 'InitTest' must either be declared abstract
                 // or implement abstract member 'v: Int'

  var v: Int

  def int(v : Int) = {
    this.v = v 
  }
}
</code></pre>

<p>I was kind of surprise by that we can't just leave values "uninitialized". In Java, it would be assigned with <code>null</code>. In Scala, it does not compile. How to do this in Scala?</p>