字符串操作

        static void Main(string[] args)
        {
            Console.WriteLine("*********");

            BasicStringFunctionality();



            Console.ReadLine();
        }

        private static void BasicStringFunctionality()
        {

            string fisstName = "Freddy";
            //转换成大写
            Console.WriteLine("转成大写{0}", fisstName.ToUpper());
            Console.WriteLine("转成小写{0}", fisstName.ToLower());
            Console.WriteLine("是否包含y {0}", fisstName.Contains("y"));
            Console.WriteLine("替换dy  :{0}", fisstName.Replace("dy", ""));

        }