C # Base------String Functions

            //String Common Functions//1.Contains (contains xx string)//2.StartsWith (whether to start with XX)//3.EndsWith (whether end with XX)//4.IndexOf (Gets the position of the first occurrence of a character in a string)//5.LastIndexOf (Gets the position of the last occurrence of a character in a string)//6.SubString (Intercept string)//7.ToLower (string becomes uppercase)//8.ToUpper (string to uppercase)//9.Replace (Replacement string)//10.Trim (remove the trailing spaces)//Case One: Determine if it is a URL: in http://start with a. com end            /*string s = "http://www.baidu.com";            if (S.startswith ("http://") && s.endswith (". com")) {Console.WriteLine ("Legal url");            } else {Console.WriteLine ("Illegal url");            } console.readkey (); */            //case TWO: Determine if the mailbox is a valid user name has a sensitive vocabulary            /*String name = "Long live XXX";            string email = "[email protected]"; if (name. Contains ("Deng Xiaoping") | | Name.            Contains ("chairman")) {Console.WriteLine ("User name has sensitive words!"); } else if (email.            EndsWith ("@qq. com")) {Console.WriteLine ("QQ Mailbox not supported!");            } else {Console.WriteLine ("Registered successfully!");            } console.readkey (); */            /*string a = "ABCDEEADSA";            Console.WriteLine (A.indexof (' e '));            Console.WriteLine (A.indexof ("CD"));             Console.WriteLine (A.lastindexof (' a ')); */            /*string a = "http://www.baidu.com: 8080 ";            Console.WriteLine (a.substring (0, 5));            Console.WriteLine (A.substring (4));            Console.readkey (); */            //case Three: Get the file name and suffix name            /*string fileName = "[ads-108] Cang jing empty. avi";            int dotindex = Filename.indexof ('. ');            String name = filename.substring (0, Dotindex);            Console.WriteLine (name);            String h = filename.substring (Dotindex + 1);            Console.WriteLine (h);            String a = filename.substring (0, Filename.lastindexof (') ') + 1);             Console.WriteLine (a); */            //Exercise one: from thehttp://www.rupeng.com: 8090/a.htm "Get domain name and port number            /*string yu = "http://www.rupeng.com: 8090/a.htm "; String y = Yu. Substring (Yu. IndexOf (' W '), Yu.            LastIndexOf (': ')-7); int L = Yu.            LastIndexOf ('/'); String d = Yu. Substring (0, Yu.            LastIndexOf ('/'));            string D1 = d.substring (D.lastindexof (': ') +1);            Console.WriteLine (y);            Console.WriteLine (D1);             Console.readkey (); */            /*string a = "HELLO";            String B = A.tolower ();//Generate a new string Console.WriteLine (b);            Console.readkey (); */            /*string a = "Hello";            String r = A.replace (' l ', ' l ');            Console.WriteLine (R);            Console.readkey (); */            /*string a = "leader";//The String object is immutable, but the declaration cannot change string b = A.replace ("leader", "* * *");            Console.WriteLine (b);            Console.readkey (); */            stringA ="I'm"; stringb =A.trim ();            Console.WriteLine (b); Console.readkey ();

C # Base------String Functions