The String.IndexOf method searched for the location of a substring in a larger string, given the substring. You can use the Substring method to do the reverse–extract a substring, given its position in the larger string.
1 2 3 4 | string s = "Itsy bitsy spider" ; string s2 = s.Substring(5); // bitsy spider (start at 6th character, extract until end of string) s2 = s.Substring(5, 4); // bits s.Substring(2, s.Length); // throws ArgumentOutOfRangeException |
Also note that the Substring method doesn’t change the original string, but just returns the substring asked for.