js_getter_example.html

<script type="text/javascript">
  class Parameters
  {
    constructor()
    {
      return new Proxy(Object.assign(this, arguments[0]), {
        get: function(target, name) {
          return name in target ? target[name] : undefined;
        }
      });
    }
  }
</script>
<script>
  var parameters = new Parameters({test: 'success'});
  console.log(parameters.test);
</script>