title: this inside function
body: <p>My question is:</p>
  
  <pre><code>function Foo()
  {
     this.foo = "bar"; // &lt;- What is "this" here?
  }
  </code></pre>
  
  <p>From what I can tell it depends on how <code>Foo</code> is used, i.e. as a constructor or as a function. What can <code>this</code> be in different circumstances?</p>