using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ConsoleApplication4{    class Program    {        static void Main(string[] args)        {                        Chinese c1 = new Chinese("韩梅梅");            Chinese c2 = new Chinese("李雷");            Japanese j1 = new Japanese("树下");            Japanese j2 = new Japanese("田中");            Korea k1 = new Korea("金秀贤");            Korea k2 = new Korea("金秀贤2");            American a1 = new American("科比1");            American a2 = new American("科比2");            Person[] pers = {c1,c2,j1,j2,k1,k2,a1,a2};            for (int i = 0; i < pers.Length; i++)            {                //if(pers[i] is Chinese)                //{                //    ((Chinese)pers[i]).SayHello();                //}                //else if(pers[i] is Japanese)                //{                //    ((Japanese)pers[i]).SayHello();                //}                //else if(pers[i] is Korea)                //{                //    ((Korea)pers[i]).SayHello();                //}                //else if(pers[i] is American)                //{                //    ((American)pers[i]).SayHello();                //}                pers[i].SayHello();            }            Console.ReadKey();        }    }    public class Person    {        private string _name;//字段        public string Name//属性        {            get{return _name;}            set{_name = value;}        }        public Person(string name)//构造函数        {            this.Name = name;        }        public virtual void SayHello()//方法 virtual 虚方法，这个方法可以被子类重写        {            Console.WriteLine("我是人类");        }    }    public class Chinese:Person    {        public Chinese(string name):base(name) //调用父类构造函数，外面传进一个name，传给父类一个name        {            //不用写代码，父类的构造器已经赋值给属性Name        }        public override void SayHello()//override重写 父类方法        {            Console.WriteLine("我是中国人，我叫{0}",this.Name);        }            }        public class Japanese:Person    {        public Japanese(string name)            :base(name)        { }        public override void SayHello()        {            Console.WriteLine("我是霓虹人，我叫{0}",this.Name);        }    }    public class Korea:Person    {        public Korea(string name)            :base(name)        { }        public override void SayHello()        {            Console.WriteLine("我是棒子人，我叫{0}",this.Name);        }    }    public class American:Person    {        public American(string name)            :base(name)        { }        public override void SayHello()        {            Console.WriteLine("我是米国人，我叫{0}",this.Name);        }    }}