using System;

public class RemoveFromStringBasedOnAChar

{

        public static void Main(string[] args)

        {

            string myString = "https://www.siit.com/net-exercises";

            char c = '-';

            RemoveLastPartOfAStringCharBased(myString, c);            

        }

        private static string RemoveLastPartOfAStringCharBased(string s, char c)

        {

            Console.WriteLine(s);

            Console.WriteLine(c.ToString());

            string result = s.Remove(s.IndexOf(c));

            Console.WriteLine(result);

            return result;

        }

        private static string RemoveFirstPartOfAstringCharBased(string s, char c)

        {

            Console.WriteLine(s);

            Console.WriteLine(c.ToString());

            string result = s.Remove(0, s.IndexOf(c)+1);

            Console.WriteLine(result);

            return result;

        }       

}

​