在 .net 8中，switch 不需要再和传统的写法一样了，会更加的方便

创建一个 .net 8 控制台项目

switch 的写法没必要和以前一样

namespace SwitchTest
{
    internal class Program
    {
        static void Main(string[] args)
        {
            int day = 3;

            var week = day switch
            {
                1 => "Monday",
                2 => "Tuesday",
                3 => "Wednesday",
                4 => "Thursday",
                5 => "Friday",
                _ => "oh shit"
            } ;

            Console.WriteLine(week);
        }
    }
}

运行：

如果将 day 设置为 30，在所有的选择中都找不到，那么结果就自动执行 _ 选项代码

namespace SwitchTest
{
    internal class Program
    {
        static void Main(string[] args)
        {
            int day = 30;

            var week = day switch
            {
                1 => "Monday",
                2 => "Tuesday",
                3 => "Wednesday",
                4 => "Thursday",
                5 => "Friday",
                _ => "oh shit"
            } ;

            Console.WriteLine(week);
        }
    }
}

运行：

遍历枚举写法一样

namespace SwitchTest
{
    internal class Program
    {
        enum color { red, yellow, green }

        static void Main(string[] args)
        {
            color myColos = color.red;
            string colosStr = myColos switch
            {
                color.red => "红",
                color.yellow => "黄",
                color.green => "绿",
                _ => throw new Exception()
            } ;
            Console.WriteLine(colosStr);
        }
    }
}

end