string result = str.Substring(0,5);

string str = "youtube";

char firstCharacter = str[0];

string str = "ararara";

string str1 = str.Substring(0,1); // returns string so [a\0]

char str2 = str[0]; // This uses the String.Chars indexer, returns 'a'

char str3 = str.First(); // returns first character 'a' same as [0]

​

Console.WriteLine("str.Substring(0,1) {0}\nstr[0] {1}\nstr.FirstOrDefault() {2}", str1,str2,str3);

            //get the 4 characters from the List of string

           // first convert the list into a string

            string result = string.Join("", lstData.ToArray());

          // now you can use the substring function

            var finalResult = result.Substring(0, 4);

string text = "Example";

char firstCharacter = text[0];

​

Console.WriteLine(firstCharacter);