#102 – Use Substring() to Extract Substrings From A String

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.

 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.