为什么会有这个警告？Program.cs(11,17): warning CS0219: The variable `year' is assigned but its value is never used Compilation succeeded - 1 warning(s) 今年是平年

using System;

using System.Collections.Generic;

using System.Text;

namespace Test

{

    class Program

    {

        static void Main(string[] args)

        {

            int year = 2015;//年份

            string text;

           text= 2015%4==0?"闰年":"平年";//请填写代码

            Console.WriteLine("今年是{0}",text);

        }

    }

}