title: Declare method outside of class
body: <p>i know i can add a method by doing:</p>
  
  <pre><code>point.prototype.move = function () 
  {
       this.x += 1;
  }
  </code></pre>
  
  <p>But, <strong>is there a way to add a method to a class by assigning a function that is declared outside of it to one of its propertie?</strong>
  I am pretty sure this can't work but it gives an idea about what i'am trying to do:</p>
  
  <pre><code>function point(x, y)
  {
       this.x = x;
       this.y = y;
       this.move = move();
  }
  
  function move()
  {
       this.x += 1;
  }
  </code></pre>