构造函数

using System;

namespace ConsoleApp6
{

    using System;
    namespace tutorialspoint
    {
        public class Student
        {
            //public Student() { }
            //构造函数，即便此处不写此函数，系统也默认填写上
            private Student() { }
            //如果这样写，则下面无法将此类实例化
        }
        class Program
        {
            static void Main(string[] args)
            {
                Student a = new Student();
                Console.WriteLine();
            }
        }
    }
}