String 字符串

 //1、定义一个有500个‘C‘组成的字符串
                string s = new string(‘C‘, 500);
                Console.WriteLine(s);

                //2、IndexOf、LastIndexOf，IndexOfAny，LastIndexOfAny
                //IndexOf和LastIndexOf 查找一个Char或一个字符串的位置
                //IndexOfAny和LastIndexOfAny 是查找 多个 Char，任意一个匹配的位置
                string a = "sdfjksdopfousdjskjsdiofuaeijoqixxnjsaopdhf";

                Console.WriteLine(string.Format("索引器 string[5]={0}", a[5]));

                Console.WriteLine(string.Format("IndexOf  op ={0}", a.IndexOf("op")));
                Console.WriteLine(string.Format("LastIndexOf  op ={0}", a.LastIndexOf("op")));


                Console.WriteLine(string.Format("IndexOfAny  a\\d ={0}", a.IndexOfAny(new char[] { ‘a‘, ‘d‘ })));
                Console.WriteLine(string.Format("LastIndexOfAny  a\\d ={0}", a.LastIndexOfAny(new char[] { ‘a‘, ‘d‘ })));