C#中的ref关键字

        static void Main(string[] args)
        {
            string temp = "a";
            Change(temp);
            Console.WriteLine(temp);

            ChangeByRef(ref temp);
            Console.WriteLine(temp);
            Console.ReadKey();
        }

        private static void Change(string temp)
        {
            temp = temp + "--changed";
        }

        private static void ChangeByRef(ref string temp)
        {
            temp = temp + "--refchanged";
        }

    class Program
    {
        static void Main(string[] args)
        {
            Pet p = new Pet(){Age = 5};
            Console.WriteLine("初始年龄是：{0}", p.Age);
            ChangeAge(p);
            Console.WriteLine("改变pet的属性值后，年龄是：{0}", p.Age);
            ChangeAgeByRef(ref  p);
            Console.WriteLine("改变pet引用地址后，年龄是：{0}", p.Age);
            Console.ReadKey();
        }

        private static void ChangeAge(Pet p)
        {
            p.Age = 10;
        }

        private static void ChangeAgeByRef(ref Pet p)
        {
            p = new Pet(){Age = 20};
        }
    }

    public class Pet
    {
        public int Age { get; set; }
    }