java代码：

package test.extend;public  class Base {	public Base(){		System.out.println("基类构造");		say();	}		public void say(){		System.out.println("我是基类");	}		public static void main(String[] args) {			Base base=new Child();					}} class Child extends Base{	 public Child(){		 System.out.println("子类构造");		 say();	 }	 	 @Override	 public void say(){		 System.out.println("我是子类");	 }}

运行结果:

基类构造

我是子类

子类构造

我是子类

在C#中：

public class BaseA    {      public  BaseA()        {            Function();        }       public virtual void Function()        {           Console.WriteLine("Base::Function");        }    }    class ChildA :BaseA    {      public  ChildA()        {            Function();        }        public virtual void Function()        {            Console.WriteLine("Child::Function");        }    }

Base:Function

Child::Function

在C++中:

class BaseA    {        BaseA()        {            Function();        }        virtual void Function()        {           cout<<"Base::Function";           cout<

Base:Function

Child::Function