Average

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

namespace cs_frist
{
    class Program
    {
        static double Avarage(List<int> nums)
        {
            int sum = 0;
            foreach(var num in nums)
            {
                sum += num;
            }
            return (double)sum / nums.Count;
        }
        static void Main(string[] args)
        {
            //建立一个list
            var list = new List<int>();
            //添加数
            for(int i=1; i<10; i++)
            {
                list.Add(i);
            }

            Console.WriteLine(Avarage(list));
        }
    }
}