空对象模式 （null object Pattern）是一种软件设计模式。可以用于返回无意义的对象时，它可以承担处理null的责任。有时候空对象也被视为一种设计模式。

C++

public class NoCommand : public Command
{
    public void execute()
   {}
}

In object-oriented computer programming, a Null Object is an object with no referenced value or with defined neutral ("null") behavior. The Null Object design pattern describes the uses of such objects and their behavior (or lack thereof). It was first published in the Pattern Languages of Program Design book series.