The IndexOf() method returns the index number of the first matched character whereas the LastIndexOf() method returns the index number of the last matched character. using System; public class StringExample { public static void Main(string[] args) { string s1 = “Hello C#”; int first = s1.IndexOf(‘l’); int last = s1.LastIndexOf(‘l’); Console.WriteLine(first); Console.WriteLine(last); } } Output: […]