创建类

并调用类的共有方法

// See https://aka.ms/new-console-template for more information
using System;
namespace HelloWorld
{
    class Program
    { 
        public int Findmax(int a,int b)
        {
            return a > b ? a : b;
        }
    }
    class Test
    {
        static void Main()
        {
            string characterName = "yulin";
            int age = 20;
            Console.WriteLine("There was a person named " + characterName);
            Console.WriteLine("Hello, World!");
            Console.WriteLine("age is  " + age);
          //  int num = Convert.ToInt16(Console.ReadLine());
          //  Console.WriteLine("num is " + num);
            Program h = new Program();
            int res = h.Findmax(2, 5);
            Console.WriteLine("res is " + res);
        }
    }
}