// Indexer on an interface: public interface ISomeInterface { // Indexer declaration: int this[int index] { get; set; } } // Implementing the interface. class IndexerClass : ISomeInterface { private int[] arr = new int[100]; public int this[int index] // indexer declaration { get { // The arr object will throw IndexOutOfRange exception. return arr[index]; } set { arr[index] = value; } } } class MainClass { static void Main() { IndexerClass test = new IndexerClass(); System.Random rand = new System.Random(); // Call the indexer to initialize its elements. for (int i = 0; i < 10; i++) { test[i] = rand.Next(); } for (int i = 0; i < 10; i++) { System.Console.WriteLine("Element #{0} = {1}", i, test[i]); } // Keep the console window open in debug mode. System.Console.WriteLine("Press any key to exit."); System.Console.ReadKey(); } } /* Sample output: Element #0 = 360877544 Element #1 = 327058047 Element #2 = 1913480832 Element #3 = 1519039937 Element #4 = 601472233 Element #5 = 323352310 Element #6 = 1422639981 Element #7 = 1797892494 Element #8 = 875761049 Element #9 = 393083859 */