using System; using System.Collections.Generic; using System.Text; class DatabaseReader { // Nullable data field. public int? numbericValue; public bool? boolValue = true; // Note the nullable return type. public int? GetIntFromDatabase() { return numbericValue; } // Note the nullable return type. public bool? GetBoolFromDatabase() { return boolValue; } } class Program { static void Main(string[] args) { DatabaseReader dr = new DatabaseReader(); int? i = dr.GetIntFromDatabase(); if (i.HasValue) Console.WriteLine("Value of 'i' is: {0}", i); else Console.WriteLine("Value of 'i' is undefined."); // Get bool from 'database'. bool? b = dr.GetBoolFromDatabase(); if (b != null) Console.WriteLine("Value of 'b' is: {0}", b); else Console.WriteLine("Value of 'b' is undefined."); // If the value from GetIntFromDatabase() is null, // assign local variable to 100. int? myData = dr.GetIntFromDatabase() ?? 100; Console.WriteLine("Value of myData: {0}", myData); } }