里氏转换

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 里氏转换
{
    class Program
    {
        static void Main(string[] args)
        {
            //字符转拼接
            string a = string.Join("*",new int[]{1,2,3,4});
            Console.Write(a);
            Console.ReadLine();
            string s = string.Join("+",1,false,'a',"张三");
            Console.Write(s);
            Console.ReadLine();

            //里氏转换(强转的时候记得用as（返回对象） 或者 is（返回bool） )
            Person a1 = new Student();
            Teacher c1 = a1 as Teacher;
            Student d1 = a1 as Student;
            if (a1 is Student)
            {
                Student b1 = (Student)a1;
                Console.Write("成功");
            }
            else
            {
                Console.Write("失败");
            }
            Console.ReadLine();
        }
    }
    public class Person
    {
   
    }
    public class Student:Person
    {
   
    }
    public class Teacher:Person
    {
   
    }

 

}