// Using variable-length argument lists. using System; public class ParamArrayTest { // calculate average public static double Average(params double[] numbers) { double total = 0.0; // initialize total // calculate total using the foreach statement foreach (double d in numbers) { total += d; } return total / numbers.Length; } // end method Average public static void Main(string[] args) { double d1 = 10.0; double d2 = 20.0; double d3 = 30.0; double d4 = 40.0; Console.WriteLine("d1 = {0:F1}\nd2 = {1:F1}\nd3 = {2:F1}\nd4 = {3:F1}\n", d1, d2, d3, d4); Console.WriteLine("Average of d1 and d2 is {0:F1}", Average(d1, d2)); Console.WriteLine("Average of d1, d2 and d3 is {0:F1}", Average(d1, d2, d3)); Console.WriteLine("Average of d1, d2, d3 and d4 is {0:F1}", Average(d1, d2, d3, d4)); } }