C#函数

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

namespace ConsoleApplication1
{
    class Program
    {
        在class Program中定义
                  有参数无返回值函数名前加void
        无参数有返回值在函数名前加返回值的类型
        //访问修饰符 函数名（参数1，参数2）
        //{
            //函数体
            //return 返回值
        //}
        /// <summary>       
        /// 无参数，无返回值
        /// </summary>
      1  public static void abc()
        {
            Console.WriteLine("无参数，无返回值");
        }

        /// <summary>
        /// 无参数，有返回值
        /// </summary>
       2 /// <param name="args"></param>
            public static int abc2()
        {
            return 1;
        }

        /// <summary>
        /// 有参数，无返回值
        /// </summary>
        /// <param name="args"></param>
       3 public static void abc3(int a,int b)
        {
            Console.WriteLine(a + b);
        }
        /// <summary>
        /// 有参数，有返回值
        /// </summary>
        /// <param name="args"></param>
       4 public static int abc4(int x,int y)
        {
            return x * y;
        }
        struct stu
        {
            public int id;
            public string name;
            public DateTime birthday;
            public double mark;
            public int age;
        }
        static void Main(string[] args)
        {
            //abc();

            //Console.WriteLine(abc2());

            //abc3(1, 2);

            //Console.WriteLine(abc4(2, 3));
            

            Console.ReadLine();
        }
    }
}