title: access outer "this" in Javascript sort method
body: <p>I have this code:</p>
  
  <pre><code>function some_object(...) {
     this.data = {...};
  
     this.do_something = function(...) {
        var arr = [...];
  
        arr.sort(function (a, b) {
           return this.data[a] - this.data[b];
        });  
     }
  }
  </code></pre>
  
  <p>However it's not working I think because <code>this</code> cannot be accessed in <code>sort</code> - another <code>this</code> is seen there for some reason, not the <code>this</code> of enclosing outer object.</p>
  
  <p>What to do? thanks</p>