Jscript.net可以用JScript 或任意NET 框架语言(如 C #,VB7.0) 通过增加extends主题词在类声明以后来继承和扩展现有类。这能力允许Jscript.net非常容易地利用 NET 平台的丰厚资源。为了说明这些,给出一个程序。这个程序扩展了NET 框架的ServiceBase 类。
// 导入需要的.net命名空间
import System;
import System.ServicePRocess;
import System.Diagnostics;
import System.Timers;
class SimpleService extends ServiceBase
{
   private var timer : Timer;
   function SimpleService()
   {
      CanPauseAndContinue = true;
      ServiceName = "JScript Service";
      timer = new Timer();
      timer.Interval = 1000;
      timer.AddOnTimer(OnTimer);
   }
   protected override function OnStart(args : String[])
   {
      EventLog.WriteEntry("JScript Service started");
      timer.Enabled = true;
   }
   protected override function OnStop()
   {
      EventLog.WriteEntry("JScript Service stopped");
      timer.Enabled = false;
   }
   protected override function OnPause()
   {
      EventLog.WriteEntry("JScript Service paused");
      timer.Enabled = false;
   }
   protected override function OnContinue()
   {
      EventLog.WriteEntry("JScript Service continued");
      timer.Enabled = true;
   }
   function OnTimer(source : Object, e : EventArgs)
   {
      EventLog.WriteEntry("Hello World from JScript!");
   }
}
ServiceBase.Run(new SimpleService());